Processing Audio using Post in python

I am working on an app that uses a recording of the user, and am using requests to send a wav file to a flask backend

Here is the code in my html file, it logs the type of the audio which designates it as a wav file

       function sendAudioToServer(audioBlob) {
            console.log('MIME Type:', audioBlob.type);
            var formData = new FormData();
            formData.append('audioFile', audioBlob);
            var xhr = new XMLHttpRequest();
            xhr.open('POST', '/process_audio', true);
            xhr.onload = function () {
                if (xhr.status === 200) {
                    console.log('Audio processing successful');
                    console.log(xhr.responseText);
                } else {
                    console.error('Audio processing failed');
                }
            };
            xhr.send(formData);
        }

And here is the python code that processes it

`@app.route('/process_audio', methods=['POST'])
def process_audio():
> print('function')
    audio_file = request.files.get('audioFile')
    if audio_file:
        audio_file.save('audio.wav')
        return 'Audio file received and saved successfully'
    else:
        return 'No audio file received', 400`

Even though it says that it is a wav file in the front end, when it gets to the backend it gets corrupted