base64-js | Base64 encoding/decoding in pure JS | Base64 library

I have written below code which is fetching 3 documents , from that document i want to display only specific filed excluding the other field

I am new to React and want to display an image downloaded as binary data. I download the image data from api call to adobe lightroom api. The api call works since the image is displayed in Postman without problems. I can also save the image data to a jpeg-file and it is displayed ok.

In React I want to do and for that to work I need to convert the binary data to a base64 encoded string. When i convert the downloaded jpeg using cat image.jpeg|base64 > base64.txt the resulting string works in my React app.

But when I try var theImage = btoa(binarydata) in React I get Unhandled Rejection (InvalidCharacterError): Failed to execute 'btoa' on 'Window': The string to be encoded contains characters outside of the Latin1 range.

After searching the issue I try use var theImage = btoa(unescape(encodeURIComponent( binarydata ))) and similar proposed solution but resulting strings from those does not turn out to be a valid base64 encodings of the jpeg as it seem (I try the result from the conversions in online base64->image services and no image is shown). I have also tried other proposed solution such as base64-js and js-base64 libraries and non of those create a valid base64 valid image that can be shown in my React code.

How do you convert jpeg binary data to valid Base64 image encoding when btoa throws latin1 exception?

I included a lot of background information to help you answer this question, however you can skip down to the heading called 'Questions' to skip to the main point.

I'm new to using Cordova, and I'm new to an existing Cordova project I want to further develop. As a result, when I look at the project files, I am not sure what are choices made by the previous developers and what are choices made automatically by Cordova. I suspect that Cordova generates a lot of files that are not created by the application developers because in my case there are over 7900 files including source code and README's, and the application was previously (to my knowledge at least) developed by only one person.

While many questions could be asked from that perspective, I would like to narrow in on a specific question to avoid being too broad. I've noted that are many files within the path structure called index.js.