I’d suggest using stake.com, they give out bonus codes on their telegram daily until christmas day, and they’re also hosting pretty big wager competitions, but you have to wager a decent amount to even get a prize. They also do weekly raffles, and the prizes are increased for christmas.
Well, all bonus codes are connected to wagering in one way or another... you need to have a decent amount wagered or you need to wager a lot before you can claim the prize. When it comes to wagering competitions it's hard to compete on those in all popular casinos... even harder with limited bankroll. I used to compete before, but I stopped with that. I don't have as much free time as I used to have, and with a small bankroll, we are forced to play for hours if we wish to compete with some whales. Of course, we need to be lucky enough to not bust the balance in the meantime.