Who is Regina's father?

In one of the final episodes of Dark, we see Claudia and Tronte talk about Regina, Tronte confessing that he wondered if he was her father, with Claudia telling him he’s not.

The familiy tree on Wikipedia lists Bernd Doppler as the father (although misspelled as Bernard). This seems plausible, but I don’t recall seeing that mentioned in the series anywhere, just a scene that made it clear he did fancy her (at an age that was completely inappropriate).

Do we actually learn who Regina’s father is?