Hello @waifu and thank you for trying Mitra!
Administrative tasks are performed using mitractl command line tool. Documentation can be found here: https://codeberg.org/silverpill/mitra/src/branch/main/docs/mitractl.md
You can change the role to admin with set-role command:
mitractl set-role <user-id-or-name> adminCurrently, admin status doesn't change much, but admin functionality will be gradually added to UI. If you're interested in any particular feature, let me know