If your concern is keeping someone from going outside you may find these helpful. They are meant to be used as child locks but I have used them on my patio slider to keep my mom from going into backyard alone or at night. They work on windows too. I have one of these locks at the upper edge of door, so out of sight and out of reach. These locks adhere with 3M peel and stick. I have had one on door about a year and it works great. Easy to put on. One note is that an adult could reach it from inside and probably figure out how to unlock. My mom has dementia and has no clue the lock is even there. She just thinks the door is broken again. I got a pack of 4 on Amazon under $20.
Sliding Glass Door Child Lock - OKEFAN 4 Pack Baby Safety Slide Window Locks for Kids Proof Patio Closet Doors No Drilling Tools Needed (Blue) https://a.co/d/eZk4FmY
Sliding Glass Door Child Lock - OKEFAN 4 Pack Baby Safety Slide Window Locks for Kids Proof Patio Closet Doors No Drilling Tools Needed (Blue) https://a.co/d/eZk4FmY
One can also use a broom handle in the floor slider, if bending down to pick-up or place isn't a problem.
If going this route, I recommend a secondary lock, as well.