Thank you @tonyyoungblood for providing the original dragon egg model:
https://makerworld.com/en/models/395708#profileId-452150

How do I modify the original model?
I initially used hollow eggs with screw threads, but this proved to be more difficult, so I switched to solid eggs. I divided the model into two parts and hollowed them out. Then, I added components to fix the magnets embedded in the plastic.

Printing instructions:

• Use the Bambu .3mf configuration file I uploaded
  • The pause has been inserted into the correct number of layers
  • After the pause, check whether the magnets are suitable—if the magnets are loose, apply a small amount of strong adhesive to the bottom of the hole
  • Repeat Step 2 to pause for the second time
• Use an STL file or other slicer/printer
  • When slicing the file, you must add two pauses to the print before the layer of the enclosed inner cylinder
  • The first pause is added to the last layer before the hole at the top of the egg is closed

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  • Add the second pause to the last layer before closing the hole at the bottom of the egg

  • 

  • Check carefully to ensure that the pause is in the correct position so that the printing can be successful
  • Print now and wait for the pause
  • After the pause, check whether the magnets are suitable—if the magnets are loose, apply a small amount of strong adhesive to the bottom of the hole
  • Repeat Step 2 to pause for the second time

Materials and settings:

• Consumables:
  • PLA
• Support:
  • It is recommended to use it at the bottom
• Floor height:
  • .16mm
• Wall:
  • 2
• Fill in:
  • 15%

The required parts

• 8 - 6x3mm magnets
• [Optional] Strong adhesive for fixing magnets