Automatic Central Locking Issue

[Geollama93]

New here and also my technical knowledge is limited so I was after some advice.
The automatic central locking has stopped working - the central locking itself is fine and works, just not automatically when I start driving. When I press the lock button from inside the car, I get a loud buzz from the left side somewhere.

I was thinking that possibly a relay has gone, but I'm unsure a) if that's correct or b) where the relays are located. I've tried Googling it, but struggling to find anything.

Would really appreciate any help if anyone has any ideas - thanks!

[Paul piper]

The doors no long lock with the push button on the key. The doors and boot lock when I hit the dead lock button in the car but not from outside. I have a boot open error come up. The wing mirrors do not fold in. If I lock the car manually only one door locks. If I lock the drive door the passenger door stays unlocked. If I then lock the passenger door the drivers door unlocks. When I push the lock button on the key it sounds like it’s trying to lock. Any ideas please