No they don't need metamask. Try the following: 1. Generate payment destination address info: web3.createaccount() on backend, or even have a list of PUB keys

No they don't need metamask. Try the following: 1. Generate payment destination address info: web3.createaccount() on backend, or even have a list of PUB keys on backend that link to ideally cold wallets. The point I'm trying to make is to isolate the destination PK's far away from frontend. 2. Send pub key to frontend and present to user in UI. 3. On backend, listen for incoming ether transfers (if you reuse wallets, consider creating a smart contract to allow a function call that allows you to pass data to identify sender to avoid duplicate payment amount confusion). Have frontend react when payment complete. Consider temp payment addresses 'hot' and move funds to cold ASAP, a common pattern you'll see. When you get into more complicated interactions, it does become a rabbit hole of complexity. I did just release an API for launching NFTs that has a concept of funding accounts: https://www.bridge-api.com/ https://www.bridge-api.com/ (beta stage). If at some point you are looking for a larger solution and want to chat where you can manage many accounts without all the hassle of gas estimation, gas price, ABIs, etc., shoot me an email (email in profile). I am looking to talk to early stage founders.