Floor for double garage

What else comes to mind .... what do I do with the drain that I actually wanted to install in the screed,? Can I simply incorporate it into the floor slab???

Just thought that with the drain, of course the drain pipe is included when pouring, that's obvious, but to insert the actual drain afterwards either reserve the space for it beforehand with Styrofoam when pouring or afterwards use an angle grinder and chisel to create the appropriate opening

So after much consideration, there is simply a large radiator, we will skip the [Betonaktivierung].