Please follow the steps below:
1) Launch Logic Pro, go to ‘Logic Pro -> Preferences -> Audio Units Manager’.
2) Make sure BIAS FX is in the list and the check box is ticked.
3) If BIAS FX is not in the list, but the file “BIAS FX.components” does exist in the location 'Mac HD/Library/Audio/Plug-ins/Components/‘, please try the the steps below : (If you don't see “BIAS FX.components” in the location 'Mac HD/Library/Audio/Plug-ins/Components/‘, that means BIAS FX plugin is not installed on your Mac, please run the BIAS FX Plugin.pkg to install the plugins)
*If you've performed all the steps above but still don't see BIAS FX plugin in Logic, please reboot your Mac and open Logic again to see if it works.*