You can't delete directories
Do you refer to managing directories in your repo (the stuff shown in the
<> Code tab) with the web-gui only?
This is currently not possible.
gitea at this time doesn't have a "full-fletched" Web-IDE like e.g. Gitlab has. You can edit files directly in your browser, but handling directories is not implemented.
You need to use a git client and a local repo on your PC to do this.
I'm going to close this, because if you clone the respository and delete the directories from there & push, then it will delete the directory.
Deleting a branch is permanent. It CANNOT be undone. Continue?