javascript - Need guidance! Trying to learn about fetch() and Promises

Question

Basically I'm trying to fetch the URL and URLPaths for two images I've uploaded (to Firebase) using the firebase function /storeImage and JSON.Stringify().

Below is the snippet of code that enables me to fetch data for the ONE image.

.then(token => {
    authToken = token;
    return fetch("myappURL/storeImage", 
     {
       method: "POST",
       body: JSON.stringify({
       image: image.base64
       }),
       headers: {
         Authorization: "Bearer " + authToken,
       }
      });
    })
    .catch(err => {
        console.log(err);
        alert("Oops! Something went wrong, please try again1")
        dispatch(uiStopLoading());
    })
.then(res => {
        if (res.ok) {
            return res.json();
        } else {
            throw(new Error());
        }
    })
.then(parsedRes => {console.log(parsedRes);

Now I want to fetch data from a second image.

What I gather, from the docs I've read, is that I should use promises for multiple async calls like what I have above. So, shouldn't something like this (see below) work?

.then(token => {
    authToken = token;

    let image =  fetch(... image: image.base64 ...);
    let coverImage = fetch(... coverImage: coverImage.base64 ...);

    Promise.all([image, coverImage])
    .then(ress => { ress.forEach(
      res => {
        process( res.json() ); 
   })
})
.catch(err => {...})
.then(res => {...})
.then(parsedRes => {console.log(parsedRes);)

Spoiler alert. I tried and it didn't. But I cannot understand why.

Answer 1

Waitting for answers