How to set concrete slab thickness

[BigBoss]

I drew the beams and on top of it I drew a plane surface using the select boundary.
Then I set the reinforcement etc.
But it doesn't show a field to set the slab thickness.

Did I add the monolithic slab in a non-proper way?

Project file:
Concrete 1.rf6 (7.4 MB)

[frank.faulstich]

@BigBoss

But it doesn't show a field to set the slab thickness.

You can set the slab thickness here:

Have a nice weekend,
Frank