Their multiply btc bonus is still available. Firstly you need to be eligible to claim the bonus. For this you need to make wager in multiply game. You can claim minimum 1000 sats bonus and maximum amount will be based on your wager. I have experienced that they offer 1k sats bonus for every 100k sats wager in multiply btc game. So the bonus rate is 1% of your wager.
I understand. Thank you!