Proposed solution

1. In https://github.com/AntoineFr/flarum-ext-money/blob/master/src/Listeners/GiveMoney.php add a -$money for if a discussion is marked as private.
2. In https://github.com/AntoineFr/flarum-ext-money/blob/master/src/Listeners/GiveMoney.php add a check for if is_private = 1 then don't grant money on a new discussion / post.

Further, in the admin settings there should be a tag picker to allow an admin to select which tags count towards gained money.
In https://github.com/AntoineFr/flarum-ext-money/blob/master/js/src/admin/index.js

You could theoretically add a setting to https://github.com/AntoineFr/flarum-ext-money/blob/master/js/src/admin/index.js to allow an admin to choose whether private discussions should count towards the gained money.

Hello @katosdev , thank you for your suggestions!

I will look at the the private discussion setting in the next weeks as it looks quite simple.
For the tag picker I'll add that to my todo list but I can't promise I will add it soon.

Hello, I started a Pull request to add an option to disable giving money if a discussion or a post is private: #44 🚀