FAQ (Frequently Asked Questions) - WoefulWolf/NieR2Blender2NieR GitHub Wiki
How do I fix the add-on not showing up in Blender?
Maybe try installing the add-on manually; instructions in installation.
How do I enable alpha (transparency) for my exported model?
In Blender, select your model's material. Scroll down to the materials Custom Properties. In this list, look for a parameter titles 0_g_1BitMask_5 (or something similar) and set this to 1.0. As expected, having this set to 0.0 disables alpha.