If you mean you didn't progress until the ending, iirc you just find the creature's names by investigating the different things, it's a bit of back and forth between rooms, like a puzzle. You kinda have to spend a bit more time clicking around and stuff to find the entity's 3 names and it should be pretty self-explanatory after that.
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Weird, I tried again and it worked fine for me. Did you check the boxes for the wrench to dislodge the key, find the dildo and then try the door?
Edit: I tried again and I think you have to masturbate with the dildo and let the dude in the hole thank you, then try the door. I think if you skip the sex scenes you don't even get to meet the agent. In retrospect I kinda like how it lets you choose if you want it to be nsfw or not.