Veneers on plaster base?

Hi
I would like to stick Riemchen onto a gypsum fiber wall. So far, the wall has only been completely covered with interior filler and sanded. Now I'm wondering if I should first roll on a plaster primer or if I can stick the Riemchen directly onto the filled wall?
The plaster primer provides a nice hard and grainy texture, which I imagine is more adhesive than the pure filler. Or is there a special primer for Riemchen?

(By Riemchen I mean these interior cladding stones that look like stone).

There is no separate primer for the tiles; you can use any plaster/adhesion primer (the cheapest one is sufficient). I would prefer that because I like to play it safe – even though it probably works directly on the wall as well. In the end, it’s just a kind of "laying tiles".

However, there is primer for tiles, just as there is primer for Riemchen. It depends on the material of the Riemchen... natural stone, plastic, clay, ceramic, etc. If no primer is applied, the adhesion warranty is void. 10 euros for a canister should be feasible.

Aha, ok then I will check when buying if there is also a primer from this very company. If there isn’t a special one, I’ll take the one I have here. I believe they are all gypsum cladding.

I believe that only for natural stone should it be a special one. That is how it was recommended to us by the [Baumarkt].

It is definitely not natural stone. The cladding for indoors is made of gypsum and the ones for outdoors, which we will probably use, are made of lightweight concrete. These must be installed on ETICS and therefore must not be too heavy. I would have found natural stone more beautiful. Thank you all!