If you want to write a text to speech app for your own language and voice from groundup, which line would you like to choose? [closed]

I want to develop text-to-speech software for my own language and voice, nothing special. Where should I start? I am from a web dev background.
give me some suggestions, articles,s or links, that I could research.

CRITERIA.
I want to use my language: Hindi
I want to use my voice too.
A offline app, kinda like “balaboka” t2e app.
Thank you…