I used OrcaSlicer
0.4 mm nozzle

Base:

• Height: 58 mm
• Width: 80 mm
• Inner diameter for lamp base: 37.8 mm
• Sparse infill: Concentric, ~10%

Lampshade:

• Height: 150 mm
• Width : 138 mm
• Top opening diameter: 71 mm

Both parts print without supports.
You can adjust dimensions in the included Blender file.