You just ask a fox to “please pee in this cup?”.
I assume it’s used to mask human smell for hunting.
I had a room mate once who used skunk scent. He slept outside a lot.
I had a cat pee in a cup. I had left the lid off the bucket of kitty litter. Inside was my cottage cheese container that I used for a scoop.
Went to get some kitty litter and ha ha.....she had gotten in there and took aim at the cup.
Not everyone that has a cat that can pee in a cup.