This tutorial shows how to convert a 3D map GLB or glTF file from https://3d-mapper.com to Wavefront .obj or printable .stl file with the free Blender.
0:13 download 3D map as glTF
1:18 glTF to OBJ
3:36 download 3D map as GLB
4:07 GLB to OBJ
Get free Blender: https://www.blender.org/