Extruder is blocked

Please close the nozzle through the operation of software, and then remove the nozzle to leave the printing model.
Please remove filament from the nozzle to prevent further blockage.
Please clean the remainder plastic of nozzle. This is video link of how to clean nozzle in Google: https://www.youtube.com/watch?v=MZnLC9WvUQ8

Please open the nozzle to work, the filament inside nozzle would automatically eject after melt.
Please add new filament in the nozzle.

Note: firstly remove the filament from the nozzle, and then, open the nozzle to heat, otherwise it will lead to more stringent blockage.