Notice:
Start a campaign mission first, then press the 'Play' button to launch the trainer.
This trainer will target the local server for single player campaign mode. It won't be able to see the game if you are not in a campaign mission.
Note, due to the way single player mode works, the local server will be terminated every time a campaign mission ends, so you will need to re-launch the trainer every time you start a campaign mission.
After downloading .zipp file rename the file to .zip and open it with any compression program