How do I calculate dihedral angles using plug-ins-again

Hi, I was just wondering how do I figure out the dihedral Angle of two planes in 3D Slicer? My plane 1, the yellow plane, is made up of 3 coordinate points, and the purple plane is made up of 4 coordinate points. I have found the plug-in Angle Planes, but the usage instructions are not very clear, so I don’t know how to use this plug-in now. I have tried the code, but it doesn’t work, so I would like to ask teachers if there is any good solution for this plug-in, why P1 or P2 can’t be chosen to create a new project?

Operating system:
Slicer version:5.7.0
Expected behavior:
Actual behavior: