I'm going crazy....No outside dryer vent?!?!?

Just bought a house in September. Bought a new dryer as well. The dryer never worked well. It took hours to dry clothes. I, dumbly, thought that it was because of the eco mode. Turns out, the vent is absolutely clogged. So, I wanted to clean it. There are 3 of us. We spent 3+ hours looking for an exterior vent. We even went and checked on the roof. Nothing. We can't find anything. This is weird. How do I find this?!?!? Any help appreciated.

Edit: The old owners said it's right above the dryer on the roof....but there are solar panels there...so....???????

Edit 2: WE FOUND IT! I used a leaf blower as mentioned in the comments. It comes out of the roof on the other side of the house. It had a cap on it...??? Anyways, took the cap off. Blew the leaf blower at both ends to clear out what we can. Put one of those little hat caps on it (hopefully that was the right thing to do). We can feel the air pretty damn well from both ends. Is there anything else we should do before we have a vent cleaning done?