Modifying a JSON via Javascript

What’s up everyone.
I’m trying to create a web application that allows you to create an animation based on a template. So let’s say I have a json animation what has a text tag somewhere, for example, the “video” starts greeting the visitor by their name “Hi Daniel”, so I want this name to change according the the logged in user’s name.
I’m trying to find documentation that would allow me to do this. I’m quite lost as to where to start.
For now I’ve been googling but finding stuff which is too high level.
I can code a fullstack web application with React and Node.js in the backend.
Any guidance on this?

I think you’re looking for dynamically change the text. JSON can not be edited, that file is stored on server side and once it’s fetched and rendered SVG on screen, you can not edit JSON. But you can change text dynamically using JS and Lottie library.

This guy has solution.

I have samples animation here , hope that might help you.