gmacar welcome, and thank you very much for donating! Flarum does not have a “ban” feature in the literal sense. The best you can do is enable extensions that handle user blocking and suspension. The “ban” is substituted with “suspend”, and that functions very closely to the traditional forum bans.
For more information on the features that Flarum has to offer, please have a look at some topics at Discuss (this is the official support forum for the Flarum software): https://discuss.flarum.org/?q=ban and also have a look at the management category in the Flarum documentation: https://docs.flarum.org/admin.
FreeFlarum mainly focuses on answering support requests related to its hosting service (e. g.: forum down, domain not working, an error occurred, etc.), not Flarum features or extension help (such questions have a higher chance to be answered and explained properly over at the Discuss forum)
