unlock it to get it swing open again to get a new filter in

unlock it to get it swing open again to get a new filter in I have Ge refrigerator the cartridge the water cartridge is in the refrigerator it swings out to the left to get it out it’s the long one that fits in the refrigerator somehow the mechanism got locked without the water filter being in there how to unlock it to get it swing open again to get a new filter in Any answers thank you