Tutorial citation:
I did not find in tutorial what you say, but instead clearly stated to copy that files and place them in corresponding folder.For proper functionality user needs to place additional files to its TNG profile folder.
Four expression files should be placed in the root profile folder, and three gcode script files should be placed in Scripts folder.
To download file(s), click right mouse button and select Save Link as…
Anyway the modbus control of spindle is working without M3, M4 and M5 files in script folder.
This was only another thing, the main problem is displayed toolpath.