First time dog owner-need advice

Hi everyone, I am really struggling and am hoping for some advice.

A day and a half ago my fiancé and I brought home a new dog, he’s 2ish years old and a black lab border collie mix. We got him from a humane society and he is heavily on puppy anxiety meds because he is pretty skittish. We have been trying to give him the meds the best we can, on occasion he won’t take one no matter what (he’s on 3 different kinds). That is not where the problem lies though, but I thought it was important to mention. We can’t get him to pee in front of us no matter what we do.

In the last 36 hours he has gone a total of 5 times, twice outside (and it was in front of my fiancé the night we got him and he rewarded him), twice on the carpet (he purposely went away from any prying eyes and did his business), and once in the crate last night right after he was let outside. Another challenge is that we live in an apartment on the second floor, so if he starts to pee we can’t quickly try and bring him outside.

We have tried taking him out every half an hour to the same spot and when he doesn’t pee we will bring him right back to the crate. It feels cruel, but that is what I have seen and been told that if he doesn’t pee outside he should go back in there so his only chances to pee are outside or in his space. I’m thinking in his previous home/situation he was punished for peeing in front of people and that might be why?

My fiancé and I both work so yesterday we tried taking him out in the morning and then crating him for 4 hours until I could come home for lunch. Then I was home for ~1 hour and we would crate him again for 4 hours before I got home again. We think that might have been too big of an adjustment especially since this is a new space for him so I am staying home with him today to take him out more periodically. We just really don’t know what to do and feel pretty helpless at this point since we can’t reward him for good behavior because he hasn’t done it really.

If anyone has any follow up questions I am glad to answer them.