Regalo Safety 28"-42" Extra Wide Expandable Baby Gate for Doorways & Bottom of Stairs, Pressure Mounted Safety Gate for Babies, Toddlers & Pets, Tested & Safe for 30 Years, American Designed and Owned

Just one like this that isn't permanently mounted: https://a.co/d/0h1sFUF5 They don't recommend these for use on the stairs because if the baby manages to push it over, they would fall down the stairs. But you don't have any stairs nearby, so it should work pretty well. We have this style to block off my office, and it's easy to take down (or step over if you have long legs, hehe).