Decode pdf base64 for native file upload?

Question

Android

Good day to all.
We write PWA applications on Ionic Framework 4 + vue.js + capacitor for native functions.
Here is the code to save the pdf file that comes with the API as a base64 string.

downloadFile() {
      let fileTo = null;
      this.getProjectPd.project.files.forEach(file => {
        if (file.id == this.getProjectPd.idDocument) fileTo = file;
      });
      let link = document.createElement("a");
      link.href = fileTo.file;
      link.download = fileTo.name;
      link.target = "_blank";
      link.click();

      //Everything is written above not really important, it's related to the browser version
      // I have issues for the code below

      console.log( atob(fileTo.file.substr(28)) )
   
      try {
        Filesystem.writeFile({
          path: `test1/${fileTo.name}`,
          data: atob(fileTo.file.substr(28)),
          directory: FilesystemDirectory.Documents,
          encoding: FilesystemEncoding.UTF8
        });
      } catch (e) {
        console.error("Unable to write file", e);
      }
    },

I'm trying to decode base64 Here is the result in the Android Studio emulator And this is what data itself produces: atob(fileTo.file.substr(28)), in the browser console. The question is how to decode it correctly?
data: atob(fileTo.file.substr(28)),

Answer 1

Just read the documentation .
You need to remove the encoding parameter and just pass the non-base64 encoded string as input.