FormData returning as empty object when trying to upload file in react

I am trying to send a file from my React client to my Flask server.

State that holds file

  const [fileToUpload, setFileToUpload] = useState(null)

form

          <React.Fragment>
            <p className='margin-top' style={pStyles}>Attach your file</p>
            <form onSubmit={handleFileUpload} encType='multipart/form-data'>
              <input
                multi='false'
                type='file'
                onChange={(e) => handleSetFileValues(e)}
              />
              {currentCheck === 'file-radio' ? (
                <button type='submit' className='btn-blue'>Upload</button>
              ) : (
                null
              )}
            </form>
          </React.Fragment>

handleSetFileValues

  const handleSetFileValues = (e) => {
    setFileToUpload(e.target.files[0])
    setFileUrlToUpload('')
  }

handleFileUpload

  const handleFileUpload = async (e) => {
    // if (fileTitle === '' || fileToUpload !== null) return;
    e.preventDefault()

    const formData = new FormData();
    formData.append("file", fileToUpload);

    const { data, success, errorMessage } = await addServiceFile(service.id, formData, fileTitle)
    if (success) {
      console.log('res', data)
    } else {
      console.log('ERROR', errorMessage)
    }
  }

Upon submision I recieve a 400 res from the server. Logging formData shows an empty object, and the file object in the req payload is an empty object as well. any advice here would be great.

addServiceFile

export async function addServiceFile(serviceId, fileToUpload, fileLabel) {
  try {
    const body = {
      file: fileToUpload,
      file_label: fileLabel
    };

    return await awsApiRequest({
      method: 'POST',
      path: `/service/${serviceId}/file-data`,
      params: {
        body: body,
      },
    });
  } catch (error) {
    return error;
  }