How can I access game files on my xbox

Xbox and other consoles prevent cheating and alterationn of the original creator intent by running secure systems. While some games have official mod support, you cannot acccess or install them outside of the game interfaces. If you eish this level of
access, use a PC.

It used to be that you could use the file explorer but that was removed by microsoft. You might be able to use one drive to access files in certain games but it isnt quite what it used to be.

Skyrim and Fallout 4 are the only games I know of on the Xbox that support mods. If it's another game, mods are not allowed and violate the terms of service.

Short answer: You can't.

Long explanation: On the Xbox console, the only way you're able to use mods is, if the game itself supports mods from an in-game menu or marketplace. Others already mentioned Fallout 4, Skyrim, Farming Simluator and the likes.

While you can mod games easily on an open platform like a PC, the Xbox is a "walled garden" and the Xbox restricts access to it's file system.

And even if you managed to get access to the file system: the console will only accept digitally signed code, with a secret key that only licensed publishers have access to.

So unless your mods have been digitally signed, they would be ignored by the Xbox's security.

You are not meant to access game files on the Xbox One. Attempting to use mods in this way is a violation of the terms of service and can get your account and your console banned.