Instructions:

1. Print with 0.2mm layer height.
2. At the end of the print, when the bed is still warm (60c for PLA), you need to take out the print and directly roll it into a cone before it cools and finally hard.

If the bed has cooled down, you can reheat it or delete the command M140 S0 from the end of the Gcode so that the bed remains warm at the end of printing.