Oh yeah. They don’t care about that and will just do their best to give you what you ask for.
In most cases a demon isn’t going to turn another human into a soulless zombie who can’t make a single decision on their own.
But free will is a tricky question anyway. How much of our will is actually free from outside influence? You buy something 'cause it was advertised on your Instagram ads, or you pick up two bags of Doritos at the store because there was a huge display stack of them right at the checkout line. You get up and go to work or school so you can progress in life and earn money to keep a roof over your head, but is that really your own true free will? People are bombarded by outside influence constantly, daily if not hourly, but still manage to tell ourselves we act under our own free will.
The likelihood is that if someone else used a demon to compel you to do something, and it worked, you probably wouldn’t even question whether doing it was your idea or not. You’d just assume you’d acted under your own free will.
If I write this comment and you accept it as being plausible, have I influenced your free will by giving the information?