I get this error https://m.imgur.com/a/caunCgQ. I am using audacity 2.3.1 64 bit. I have installed the 64 bit plugin. Any plugin I have tried will not enable without giving this error.
You are not. There isn’t a 64-bit version of Audacity for Windows. Audacity 2.3.1 for Windows is a 32-bit application and only supports 32-bit plug-ins.
Note also that Audacity does not support VST instruments (VSTi).