hey, I am implementing erc721 token, can somebody explain me how to get the tokens that a belongs to an address? I am using open zeppelling

Use a mapping for addresses and their balance

Then simply call a getter for the desired address

Depends if you're using a smart contract or off-chain program. If using a smart contract use an interface to define the functions you want to call

if you are using off-chain, providing the function or state variables are marked as public you can call those directly

if they are private, you could inspect storage slots

i believe IDEX is currently working on a solution but im not 100% sure