Can we save the data in JSON format and retrieve using Grav folder struture ?
A JSON API is going to be bundled in the core in the future.
In the meantime the plugin Grav JSON Pages API looks like what you need.
How to het the Grav JSON Pages API to work?
What is the exact request i have to do? I’ve tested it with postmen, but i dont get any json response?
You’d better post an issue on the Plugin repository itself so you’ll get a reply from its developer, which might miss this post.