yeah, i'd be extremely sceptical of that. There's a lot of highly exploitative actors in Germany's sex industry, they frequently resort to manipulation of vulnerable groups and trick them into coercive, slavery-like working conditions. Newly arriving refugees who can easily be misled about their legal situation and protections here are often easy targets for that kind of approach, and this goes doubly for groups who are vulnerable in more than one way, such as the Ukrainian trans sex workers explicitly mentioned here. Stuff like taking away and withholding legal documents and using the threat of deportation are common practices among pimps. so yeah, that add raises a ton of red flags.

also note that fetishization of Eastern European women in general and Ukrainian women in particular is massive in Germany. searches for Ukrainians on porn sites from German IP adresses skyrocketed almost immediately when the war began, and refugee aid orgs have had to put policies in place against creeps offering to take in refugees only as long as they're single women.

Edit: Somebody provided further links and this could actually be a peer-to-peer network of trans, inter and NB sex workers instead of a grooming approach. i'm not familiar with the org, but they work with other orgs who actually consist of active or former sex workers, so i may be overly cautious here.