You can record a video and send to the group, like daily beginners workout etc in a Telegram group probably would work.
But still you need to understand who is your ideal buyer or Perfect Buyer Persona.
If I'm going to gym, I probably don't need you.
So find your ideal buyer and then find out what's their problem, don't ask solution from them, just discover as much problems as possible before you even start, you will be able to see insights that gives you a change to kickstart a MVP to test it out.