Earn money with Minecraft?

There's supposed to be a page on which you can offer buildings built from Minecraft for real money. Does that actually work? If so, what is the name of this page and do I have to pay taxes there?

You have to pay taxes for every income you have whether it works kp but you have to pay taxes

Fiver

If I create an account on Fiver and sell my Minecraft structures, how exactly do I have to do that? How can I then hand over my building to the buyer and do I have to pay taxes?

Such a false and stupid statement. Go find out about it before you tell such nonsense here!

Then explain to me why I'm wrong, he makes money with it and of course has to tax it

Let it through: https://www.steuern.de/einkommensteuergesetz.html