yes, its that panel. thats called the door card or door trim.
this pic is from a classic impreza so its probably a bit different, but look
here.
when you take that panel off, the lock and metal rods in that pic are within the door. you will probably find one end of one of the rods has come lose.
I would suggest you take the door card off, then operate the central locking and see what moves and what doesnt