Minor using a btc atm kicked out

I was in a gas station and this is the 2nd time im buying at an atm from this location and ive done it a ton at a different location. As I was buying the btc this lady comes up and says its illegal for a minor and I need a parent even though it doesnt need id? Is it illegal or is there another rule against it? I was using a coinflip atm in ohio. I don't even think the lady was the owner/manager of the station but maybe she was.