Sign up on Cloudinary
Go to the dashboard you need the cloudname
Then go to settings -> upload and add a new upload preset. You need to copy the name and you need to set it to unsigned.
Everything happens in index.js in this example
Add your preset name and cloudname here
formData.append('upload_preset', '<your name of the preset>');
const data = await fetch('https://api.cloudinary.com/v1_1/<your cloud name>/image/upload', {
method: 'POST',
body: formData
}).then(r => r.json());The url of the uploaded image is in the data of the response secure_url - this url would be stored in mongodb. You could make another request to an api route to do that.