A friend of mine want to transfer money to my revolut bank account. How do he actually do this from America? Also he has a credit card. Is wire an option or how does this work

The bank should provide guidance on wire transfers. Note an intermediary bank may be required.

If their platform does not offer wires via online banking just have them go to the bank. Its a routine transaction but he might have to pay a small fee when doing it at the counter. Obviously they will need your account details.

when you reach out to your bank(s) mention that you made a help thread on d2jsp so that they can add it to the transaction notes

I suggest looking into Currencyfair, it is pretty much guaranteed to be one of the cheapest possible ways to move your money. Worked great when moving my USD to CAD.