To use the plugin in MPE mode, please, make sure you’re using a MPE-compatible controller and a supported DAW. Please, take a look at this list by Roli to make sure your is.

On the controller’s side:
Please, make sure your controller is mapped per Roli’s specs. Below you’ll find the configuration for the ROLI dashboard, but I’m sure you‘ll be able to adapt it to your needs if you’re using a different controller. 

MPE mode: enabled
Slide CC: 74
Press: Aftertouch
Glide: Pitchbend

Inside the plugin:
Load up a patch that supports MPE. This is indicated by an MPE button displayed on the bottom part of the interface. Clicking on that button will disable CC1 automation and map the plugin to respond to MPE.