It is highly unlikely to get you into any trouble. It is also highly unlikely to be worth your time.
That said, depending on your contract, your institution and your program, if you do get into trouble with it, it could cost you your fellowship spot.
If there are more legitimate moonlighting opportunities I would encourage you to pursue them instead. And TBH, the only people making money on telehealth are the ones running the companies. But if you want to proceed, go ahead, just don’t tell anyone what you’re up to.