If you prefer not to use an external trainer, you can enable the game's native cheats, which are just as effective for most players:
Right-click the trainer and select "Run as Administrator." Launch the Game: Start your Warband repack.
: Add 10 points to attributes, skills, or weapon proficiencies at a time.
Shady sites often bundle trainers with "bloatware" or actual viruses.
Mastering Calradia: The Ultimate Guide to the Mount & Blade: Warband Trainer (v1.174)
Before using an external trainer, ensure "Enable Cheats" is checked in the Mount & Blade: Warband launcher configuration menu. Steam Community
Here is a feature profile for the trainer: