Hi, 04 V70, non turbo

Have only one key fob for the car.
I was gonna go to dealer to order service key ( one with no remote) but recently learned that my door can be locked/unlocked with remote but not with key blade. When inserted into door lock cylinder, key turns but nothing happens
Key blade works perfectly in ignition and starts engine.
So I am suspecting something is wrong inside the door.
Anybody here have any suggestions? Thanks