Check if spool is not jammed up and fitted with correct direction as shown in manual page no 28.
After clearing spool jamming remove the feeder tube from extruder click retract button with speed of 100mm/min set retract length to 50mm and try and pull out the filament manually, once the filament is out cut the filament initial part and insert again.
Also check bed level, if bed is very close to the nozzle it will not allow extruder to extrude any material from the head.
- if issue is still nor resolved follow nozzle cleaning procedure.