As I know, when buying on Epic UE4 Marketplace from Germany, invoices use reverse charge. So price on the market place shop is without VAT and also without VAT on the invoice. And that’s ok in my opinion.
For invoices produced by Epic, I had never a problem, because all invoices had a clear “reverse charge” text on the invoice. Which is OK by law as I know.
But I had problems over several months buy payment methods which produce a invoice from Xsolla. I needed several months and tons of emails to get invoices which are conform to EU VAT law.
For us, I used our official company name and our official VAT number (EU / European VAT number in our case).
But I do not understand the question I think.
Perhaps you can tell a bit more. If you bought assets and used xsolla to pay and if you are also stationed in EU, your Invoice should show no VAT. See the original Epic invoices as good reference, they also use Reverse Charge for European Customer when buying assets. But that was not the only problem we had with xsolla invoices. They are not focus on B2C market and simply miss also other rules for conform EU invoices for B2B:
Market place assets were not listed
VAT and I think also the address of xsolla was missing
As I said, we had long conversions with xsolla until getting invoices which are EU VAT law conform.
For me, I will never use any xsolla payments to buy on ue4 market place again.