Milja If I trie to do it, I need to pay 9 euro extra?
There's currently a display bug in the update introduced with the recent update. It'll will be fixed with the next update probably. If you have an Easy Money or Easy Green plan, you can have up to 3 physical cards + additionally up to 5 virtual cards for free. That hasn't changed. (Check the Pricing Sheet if you want to know every detail.)
You should be fine to just go ahead and order your 3rd virtual card without having to pay a fee for that. (If you have downgraded to an Easy Bank plan, then of course other costs apply. But as long as you're on Easy Money or Easy Green, you're fine.)