This limit allows you to limit the amount of money you can lose within a set period of time. You can find it here: go to the menu in the top-left corner, then click on "Account" → "Responsible Gaming" → "Loss Limit".

How does it work? You set a maximum amount which you can lose in a day, week, and/or month (30 days). Once your losses reach the maximum amount set, you will no longer be able to participate in games until the limit expires. You can apply this limit to both poker and casino games.