If the extruder can't move properly rule out the options first.
Remove the tube and extruder for a good cleanout - PLA love to leave dust and pieces behind in the most unusual places.
Then check if the grub screw on the extruder is tight - these little bastards are often overlooked....
Clean the hobbed bolt or whatever transports your filament including the bearing on the other side.
Put the exturder together and check if the filament moves through.
Set the pressure so the filament is transported safely without too much deformation.
Add the tube connector and make sure nothing can get caught there, add the tube and let the extruder run till the filament is through.
If all that comes out fine you should be good to go again unless your hotend/nozzle plays up too.