Nano game engine integration, where to put wallet keys?

Hello, I'd like to make a (ba)nano plugin for a game engine (Godot) for a game idea I have, I want the user to own their own coins (no custodial wallet on a server that the user logs into), so I'm wondering what is the best way to achieve this. I assume I can consult a remote service to get wallet balances and transactions, and to publish transactions, but do I need to keep the wallet keys in the client with the game, or is there a way to talk to an already established wallet (like Natrium) to have the wallet sign and publish transactions for me ? Having the private keys in the game would be too much responsibility and I'd like to avoid it, I feel like wallets already do this and the users will be familiar with them, and I'm no security expert. Is there something like the "wallet connect" protocol for nano wallets ?

Thanks !

while i don't know the specifics for game engine integration, the high level architecture should be the same as nault: keep them encrypted only on the client side, only decrypt them temporarily when needed with a user given password (cache policy chosen by you)

welcome by the way!

Store it in persistent storage of the game in an encrypted vault.