Hi Elisa, attached are the gates we use now. They require someone to pinch the grey button and slide it back to release the midsection to open. It is a one handed action. My husband with moderate dementia can operate it although you could put a lock to prevent it from opening which of course might be a pain for you.
We had another type epen/close mechanism which was harder and my husband had trouble opening because it took two hands and was more complicated which might workbetter for you. If you start looking on chewy.com pay attention to how they open mechanism works.