Firebase functions Error file is not defined

I’m currently building my first ever project on Firebase. I just deployed my project on it, and after few hours of debugging, I’m mostly lost, and have no more ideas on how to resolve it. I don’t know why when I’m uploading my file, I receive a 500 error. I’ve some errors in the consoel, which are:

[Here’s the link to the console][1], and here is my component:

export const GenerateNew = () => {
  const [image, setImage] = useState(null);
  const [style, setStyle] = useState('Gamer');
  const [loading, setLoading] = useState(false);
  const [isDropdownOpen, setIsDropdownOpen] = useState(false);
  const [credits, setCredits] = useState(0);
  const [showCreditAlert, setShowCreditAlert] = useState(false);
  
  const dropdownRef = useRef(null);
  const { currentUser } = useAuth();

  useEffect(() => {
    if (currentUser) {
      const userDocRef = doc(db, 'users', currentUser.uid);
      const unsubscribe = onSnapshot(userDocRef, (docSnapshot) => {
        if (docSnapshot.exists()) {
          const userData = docSnapshot.data();
          setCredits(userData.credits || 0);
        }
      });
      return () => unsubscribe();
    }
  }, [currentUser]);

  useEffect(() => {
    const handleClickOutside = (event) => {
      if (dropdownRef.current && !dropdownRef.current.contains(event.target)) {
        setIsDropdownOpen(false);
      }
    };
    document.addEventListener('mousedown', handleClickOutside);
    return () => document.removeEventListener('mousedown', handleClickOutside);
  }, []);

  const onDrop = useCallback((acceptedFiles) => {
    setImage(acceptedFiles[0]);
  }, []);

  const { getRootProps, getInputProps, isDragActive } = useDropzone({
    onDrop,
    accept: { 'image/*': ['.jpeg', '.jpg', '.png', '.gif', '.webp'] },
    maxFiles: 1,
    disabled: !!image
  });

  const handleSubmit = async (e) => {
    e.preventDefault();
    if (!image) {
      alert('Please select an image first.');
      return;
    }
    if (credits === 0) {
      setShowCreditAlert(true);
      return;
    }

    setLoading(true);

    try {
      const formData = new FormData();
      formData.append('image', image);
      formData.append('style', style);

      console.log('FormData content:');
      for (let [key, value] of formData.entries()) {
        console.log(key, value);
      }

      const response = await axios.post(`${API_URL}/generate`, formData, {
        headers: { 'Content-Type': 'multipart/form-data' },
      });

      const generatedImageUrl = response.data.output;

      // Sauvegarder les images dans Firebase Storage
      console.log('start save dans FBS');
      const originalImageRef = ref(storage, `original/${currentUser.uid}/${Date.now()}_${image.name}`);
      console.log('Saved dans FBS');
      await uploadBytes(originalImageRef, image);
      const originalImageUrl = await getDownloadURL(originalImageRef);

      const generatedImageResponse = await fetch(generatedImageUrl);
      const generatedImageBlob = await generatedImageResponse.blob();
      const generatedImageRef = ref(storage, `generated/${currentUser.uid}/${Date.now()}_generated.png`);
      await uploadBytes(generatedImageRef, generatedImageBlob);
      const firebaseGeneratedImageUrl = await getDownloadURL(generatedImageRef);

      // Sauvegarder les informations dans Firestore
      console.log('Save dans FBS');
      const setupsRef = collection(db, 'generatedImages');
      const setupsSnapshot = await getDocs(query(setupsRef, where('userId', '==', currentUser.uid)));
      const setupNumber = setupsSnapshot.size + 1;
      console.log('Saved dans FBS');

      await addDoc(setupsRef, {
        userId: currentUser.uid,
        originalImage: originalImageUrl,
        generatedImage: firebaseGeneratedImageUrl,
        style: style,
        title: `Setup #${setupNumber}`,
        createdAt: new Date()
      });

      // Mettre à jour les crédits de l'utilisateur
      const userRef = doc(db, 'users', currentUser.uid);
      await updateDoc(userRef, { credits: increment(-1) });

      setLoading(false);
      alert('Image generated and saved successfully!');
      
      setImage(null);
      setStyle('Gamer');
    } catch (error) {
      console.error('Error:', error.response ? error.response.data : error.message);
      setLoading(false);
      alert('An error occurred. Please try again.');
    }
  };

  const styles = ['Gamer', 'Aesthetic', 'RGB Free'];

And my index.js file, my firebase functions:

const functions = require('firebase-functions');
const express = require('express');
const multer = require('multer');
const Replicate = require('replicate');
const cors = require('cors');

const app = express();

// Configuration de Multer avec gestion d'erreurs
const upload = multer({
  storage: multer.memoryStorage(),
  limits: { fileSize: 10 * 1024 * 1024 }, // Limite à 10MB
}).single('image');

app.use(cors({ origin: true }));
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

const replicate = new Replicate({
  auth: functions.config().replicate.api_token,
});

const styleDescriptions = {
  'Gamer': `Upgrade this setup to create a gaming setup, with aesthetic rgb lights...`,
  'Aesthetic': `Transform this setup into a minimalist and visually pleasing design...`,
  'RGB Free': `Enhance this setup to create a professional and sophisticated environment...`
};

app.post('/generate', (req, res) => {
  console.log('Received generate request');
  
  upload(req, res, async function(err) {
    console.log('On arrive ici');
    if (err) {
      console.error('Upload error:', err);
      return res.status(400).json({ error: 'File upload error', details: err.message });
    }

    console.log('File uploaded successfully');
    console.log('File details:', file ? { originalname: file.originalname, size: file.size } : 'No file');
    console.log('Selected style:', style);

    try {
      const { file } = req;
      const { style } = req.body;

      console.log('File details:', file ? { originalname: file.originalname, size: file.size } : 'No file');
      console.log('Selected style:', style);

      if (!file) {
        return res.status(400).json({ error: 'No image file provided' });
      }

      const styleDescription = styleDescriptions[style] || '';

      console.log('Preparing input for Replicate API');
      const input = {
        image: `data:${file.mimetype};base64,${file.buffer.toString('base64')}`,
        prompt: styleDescription,
        guidance: 3.5,
        num_outputs: 1,
        aspect_ratio: "1:1",
        output_format: "webp",
        output_quality: 80,
        prompt_strength: 0.80,
        num_inference_steps: 28
      };

      console.log('Sending request to Replicate API...');
      const output = await replicate.run(
        "black-forest-labs/flux-dev",
        { input }
      );

      console.log('Replicate API response received');
      res.json({ output: output[0] });
    } catch (error) {
      console.error('Error in generate function:', error);
      res.status(500).json({ error: 'An error occurred while generating the image', details: error.message });
    }
  });
});

// Export the Express app as a Firebase Cloud Function
exports.api = functions.https.onRequest(app);

It sounds like this for (let [key, value] of formData.entries()) {console.log(key, value);}

is the only console.log which is working. Nothing else sounds working.

Do you guys have any idea?

Appreciate it!
[1]: https://i.sstatic.net/nutf6I9P.png