Rebuy is a possibility to get up to 500 chips for free 5 times a day so that you can try to win back. When your balance falls below 500 chips, it is enough to sit at the table with the lowest bets and chips will be added automatically.

 

You can also get the rebuy in the bank of the game:

 

If you spent all 5 rebuys there will be a timer in the bank that will show when the limit is refreshed: