loadAsync in JSZip is not waiting to get completed

I am using JSZip library on browser UI and having a “content” which I am passing as body for creating a zip.

var contentDiff: async function(content){
      zip = await JSZip.loadAsync(content, {base64: true});
      return zip.files;
},//other functions below this

Now, I am new but this “zip.files” comes as undefined in a later method call, even after calling await.
Kindly suggest what is missing in this js.

I tried different variations of async await and promises, but all in vain.