Is it possible to update the manifest.json file from your app

I am new to coding and am using create-react-app to build my first app, and was wondering if it is possible to update the manifest.json file from within my app.

For example, if my folder structure is:

public
   >index.hmtl
   >manifest.json
src
   >app.js
   >index.js

would it be possible for me to write some code to update the contents of manifest.json? Or would that not work because it is not in the src folder?

The current contents of the manifest.json file are this:

{
  "short_name": "React App",
  "name": "Create React App Sample",
  "icons": [
    {
      "src": "favicon.ico",
      "sizes": "64x64 32x32 24x24 16x16",
      "type": "image/x-icon"
    },
  ],
  "start_url": ".",
  "display": "standalone",
  "theme_color": "#000000",
  "background_color": "#ffffff"
}

But let's say I wanted to change the "icons" array to this:

  "icons": [
    {
      "firstName": "Jon",
      "lastName": "Smith",
      "id": "1"
    }

Is that possible?