Hi, wanted to know how marketplaces like OpenSea or Mintable take 2,5% fee? I want to create marketplaces like them, however, looking at their smart contract didn't give me any hints. I'm thinking to use the ERC721PresetMinterPauserAutoId
however, it seems it doesn't cover the royalty part?
I also am looking to EIP-2981 which has promises about royalty, but it seems still not yet implemented. And I suppose this was supposed to help the artist take 2,5% even if the nft will be sold off platform right? How then marketplace like OpenSea retain the 2,5%?