Bet365 free bet rules

Took a free bet offer but now I'm not totally sure what counts towards withdrawal. I placed a few bets using the promo credit but didn’t see any balance change after a win. Do they only let you keep the winnings and not the stake when it’s free bets, or is there some other playthrough thing I’m missing? I like jumping around crypto casinos for promos but this feels way more confusing than usual.

If you’ve cleared these before, how did it actually work for you? Any tricks to make sure you don’t just waste the bonus?