Get API result in JSON format

Hi,
I’m using LT in my live site. And Its absolutely working. this is my site link: https://ltchecker.lsgsoft.com/
I’m checking it using LT API, now I want to customize my own textarea and Context menu.
Is there any way to to send API request to server and get its(textarea text) result in JSON format? And adjust that inside my own context menu? Like below wrong sentence my context menu show that particular correction.
I’ve designed my textarea & context menu but don’t know how to send its request to the server and get in JSON format and show inside my context menu.
Any bit help would be a great favor.

LalaRukh

@dnaber Seeking your response & help please.