How are the European countries paying Russia in Rubles?

As far as I understood, for the purchase of Russian gas, European countries can't pay Russia in EUR because of their sanction on Russia. On the other hand, as per Putin's decree, Russia only accepts Rubles.

However, last time I read, European countries are paying EUR to GazpromBank, and the bank is converting EUR to Ruble. That means gas customers are paying in EUR, not Ruble.

So, how is that consistent with Putin's decree?