I am making a project to add users in MongoDB but I am getting ERR_HTTP_HEADERS_SENT

    import User from '../model/user.js';

// Get all users
export const getUsers = async (request, response) => {
    // Step -1 // Test API
    // response.send('Code for Interview');
    try{
        // finding something inside a model is time taking, so we need to add await
        const users = await User.find();
       return response.status(200).json(users);
    }catch( error ){
        return response.status(404).json({ message: error.message })
    }
}

// Save data of the user in database
export const addUser = async (request, response) => {
    // retreive the info of user from frontend
    const user = request.body;
    response.send("hello");
    
    

    const newUser = new User(user);
    try{
        await newUser.save();
        response.status(201).json(newUser);
    } catch (error){
        return response.status(404).json({ message: error.message});     
    }
}

// Get a user by id
export const getUserById = async (request, response) => {
    try{
        const user = await User.findById(request.params.id);
         response.status(200).json(user);
    }catch( error ){
         response.status(409).json({ message: error.message })
    }
}

// Save data of edited user in the database
export const editUser = async (request, response) => {
    let user = await User.findById(request.params.id);
    user = request.body;

    const editUser = new User(user);
    try{
        await User.updateOne({_id: request.params.id}, editUser);
        response.status(201).json(editUser);
    } catch (error){
        return response.status(411).json({ message: error.message});     
    }
}

// deleting data of user from the database
export const deleteUser = async (request, response) => {
    try{
        await User.deleteOne({_id: request.params.id});
       response.status(201).json("User deleted Successfully");
    } catch (error){
        response.status(406).json({ message: error.message});     
    }
}

This is the error I am receiving
node:internal/errors:464
ErrorCaptureStackTrace(err);
^

Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
at new NodeError (node:internal/errors:371:5)
at ServerResponse.setHeader (node:_http_outgoing:576:11)
at ServerResponse.header (C:UserseggfrDesktopdemocrud-servicenode_modulesexpresslibresponse.js:771:10)
at ServerResponse.send (C:UserseggfrDesktopdemocrud-servicenode_modulesexpresslibresponse.js:170:12)
at ServerResponse.json (C:UserseggfrDesktopdemocrud-servicenode_modulesexpresslibresponse.js:267:15)
at addUser (file:///C:/Users/eggfr/Desktop/demo/crud-service/controller/user-controller.js:29:37)
at processTicksAndRejections (node:internal/process/task_queues:96:5) {
code: