harsh588
Here is info about extension development for Premiere Pro:
A good point to start is here:
https://github.com/Adobe-CEP/Getting-Started-guides
https://github.com/Adobe-CEP/CEP-Resources
https://github.com/Adobe-CEP/Samples
https://github.com/Adobe-CEP/Samples/tree/master/PProPanel
https://ppro-scripting.docsforadobe.dev/
Great examples to learn from. Basically, Adobe extensions are a website UI (html, javascript, nodejs support) that talks to ExtendScript (old version of javascript), which is used to invoke commands for Adobe software.
Know that Adobe is currently in a transition period, where they switch from CEP (Common Extensibility Platform, structure I described you above) to UXP (Unified Extensibility Platform). UXP will merge website and ExtendScript commands in one context.
Also I can recommend great course by Davide Barranca, he describes Photoshop extensions, but it is almost the same for Premiere Pro. His website is also great for some tips!
https://www.davidebarranca.com/
https://www.htmlpanelsbook.com/