If I understand correctly I would have to register and verify account on Archway to be able to use services that are offered?
Correct, you register on the platform with your email and phone number. There is no KYC up to 1000€, and it's light touch above that.
I am reading FAQ page and there is a part saying that you are creating bank account for customers in EURO or USD.
I don't want to do this if I only want to create Invoices, that can be done for free and without fees with different services.
Ok that is wrong, our FAQ is currently confusing sorry about that! EUR or USD accounts are potential new features we may offer in certain countries in the future but that is unrelated to the basic invoicing service.
You do NOT need to have any bank account (and we don't offer this) if you just want to create invoices and get paid in crypto
