So here is the home assistant link which is already develop website but I am also developing same product with less integration so I want to customize the website so how to do it

here is website link- https://demo.home-assistant.io/#/lovelace/home

here is the git hub link where they have use typescript but I am not able to find the html or any functionality inside them – https://github.com/home-assistant/frontend

can somebody please explain it to me as I am totally confused over it.

I have tried to understand it from youtube but I am not able to understand it. I have also tried to explore through code but it was useless.

I am expecting that somebody can scrutinize this problem for me and provide me solution as soon as possible.