Getting rewards is always fun. You can get something free or with a little effort. That's one of the reasons for using the Brave browser, because you are getting BAT in exchange for seeing some ads. Another reason for using Brave as a Browser is to take back control of your data with blocking ads and stopping trackers.
After each month, you can claim your earned rewards to your wallet via chrome://rewards. Unfortunately, if you are using Brave on a degoogled phone, this causes the app to crash. I am using a Google Pixel 5 with the current GrapheneOS version (Android 11) and ran into this problem (with Brave 1.24.86). But I am not alone, there are several posts on reddit from users who got the same issue.
There is an open issue regarding this problem on the Brave Github page and the devs are aware of it. The root cause seems to be related to some SafetyNet changes which need working Google Play Services. Unfortunately, the issue is still in backlog and the last comment on it was 21 days ago.
If you run a stock OS and can enable the Google Play Services, you can claim the rewards and afterwards turn the settings back off. If you run a Custom ROM like LineageOS, CalyxOS or GrapheneOS, you can not claim them currently. Even with microG, the app will crash. So you need to be patient and wait for a fix. I will keep an eye on the Github issue and hope for some updates there.