Hi, Press down on the handle, while lifting the door, (from the handle). If this works, your door has "Dropped" and the weight of it, is jamming the locking mechanisism. The solution, is to remove the "Panal" or "Glass" units, and wedge the door frame up, from the top corner, (furthest from the hinges) of these units, with plastic wedges. I've done this many times.
Regards,..Geoff. (Mr. Fixit)

Hi,
It sounds like the multipoint lock has failed within the gearbox. You will need to call out a double glazing repair specialist or a locksmith.
I encounter this on an almost daily basis.
The procedure is to first open the door by using a door spreader followed by an air wedge (if required), locate the rollers/hooks and push them back to the open position .
Once the door is open then you can get an ID on the gearbox and make the relevant orders.
愿一切都好！
Zach at Windows Revived UK Ltd