Bathtub sealing tape for slanted walls

Hello everyone,
we are renovating the bathroom and have had new pipes installed as well as a new shower tray and shower basin fitted. Since I am not very familiar with the installation, I wanted to rely on a professional company (just as the clients of my profession can also rely on it being done correctly).

Now I don’t know what to do, because from my understanding, besides the soundproofing tape, a sealing tape should also be applied and the basin sealed to the wall, so that afterwards the sealing tape can be coated with liquid foil.

However, I don’t see any sealing tape in the installation (is there soundproofing tape that also seals?!) and I also don’t see that the basins fit flush with the wall. The foreman said the walls are uneven and that this would be compensated by the adhesive for the tiles. If the flexible adhesive contains epoxy resin, would that be sufficient for sealing? For me as a layman, no, but maybe I just don’t know enough. Is there a way to seal it afterwards with tape?

I need help and would appreciate any feedback and tips!

Pictures

That looks unfinished. Ask next time they are here.

Take a look at PCI Pecitape - on the PCI homepage. There is a nice video for laypeople showing how such a waterproofing should look.

Spoiler: Your master is talking nonsense.

Thank you for your feedback, I had almost guessed it.

It was said that everything was finished and when asked, he said the sealing tape was already on (as in the photos) and such tape exists for folding over and also without folding...

This claim is therefore simply a lie, right?

The demand for defect rectification because it does not comply with the state of the art is then more than justified.

And I saw that he had not even fixed the shower tray to the wall, underneath there are only the 4 feet and pipes. If it would be better for us that way, he would still do it. It’s disgusting.