So many good solutions here. Here's mine.
I have a slippery hardwood floor. I found a piece of 1 X 3 about four feet long. I put that under the machine with my food pedal attached to it with large rubber band. The far end of the wood bumps into the sofa bottom, so can't go anywhere. My two feet keep the front end where it belongs and I never have to go looking for it.
Maybe instead of a sofa stop, there may be a wall there which would stop it. Two or three feet long might be enough for your situation.
Good luck!