Transferring Between User and Other Account, and Vice Versa

I am using moralis for my website and want to implement something where the “system” would transfer a NFT to a user, and a user would transfer MATIC (on the mumbai network) to the “system”, and vice versa.
How could I implement this (it might be basic, but I’m still a beginner).
Also, I saw some stuff on transferring in the moralis docs, but I don’t know how I would choose the sender (and how I could make the sender either the user or the “system”).

With Moralis transfer function you can only transfer one asset.

To do this you need a marketplace contract. The exchange of erc20 and NFT happens at the marketplace contract.

Check the moralis tutorials from below link on how to implement this.