The wagering requirement (also called playthrough or rollover) is the most critical part of any bonus. Mechanically, it is a multiplier that dictates how many times you must bet the bonus amount before it becomes withdrawable. For example, if you have a bonus, you must place bets totaling the bonus amount multiplied by the requirement figure.
Operators implement these requirements to prevent "bonus abuse," where a player might claim a bonus and immediately withdraw it without actually playing. Without these rules, the platform could not sustainably offer extra credits to all users.
It is important to check if the requirement applies only to the bonus amount or to the deposit plus bonus. The latter requires significantly more betting volume to clear. You can find the exact multiplier and the current status of your progress in the promotions tab of your account profile.