Take out the existing lock and bring it to a home improvement or hardware store and purchase a new lock that will fit your patio door.
How to fit patio door lock.
Key lock and housing product code.
Then on the door where the slide bolt will go drill a hole where the bolt will be placed.
When you have added the main body of the lock and the lock bolts to the door then you can add the cover plate.
Once the holes have been made you can then screw the lock into the door.
How to install a lockking security bar lock for a patio door or sliding glass door.
If either fix does not make the patio door lock correctly or at all remove the door lock with a screwdriver and fit a replacement lock into the recess.
Easy to install and easy to.
These should line up with the lock.
Made in the usa of aircraft quality aluminum.
When the lock is screwed into place take the bolts and fit them into the door frame facing the lock.
Using your magnet clean up all the metal shavings around the holes.
Using the correct drill bit drill the holes that you have marked.
Then screw in the base and bolt sides drawing the bolt back into lock position.
Replace the patio door lock.