I have been able to activate Infinite Stats and skills, but have been unable to use Infinite Action Points and Hit Points. The Option toggles, and after a few seconds toggles off. I have done this in combat, while taking damage and using AP.
I have not been able to test the Ammo and Weight toggles.
Please Advise
Welcome to the community. 
If you meant the game called Atom RPG: Post-Apocalyptic Indie Game, then the game updated recently. Therefore the trainer will also be in need of an update.
This link will explain how to request an update for trainers: How do I request an update for games? - WeMod Support.
If you meant the game called Atom RPG Trudograd, we currently do not have a trainer for this game, but it can be voted for a trainer to be made via the WeMod desktop app.
Don’t forget you have a referral link to invite others to vote while being rewarded for it.
How do I find my referral link? - WeMod Support.
And we also have a forum section where free games are posted to help pass the time and accumulate WePoints while waiting for updates to trainers. Deals & Giveaways - WeMod Community.