No sound from plugin after install on FL Studio 20 following install instruction at Plugin Boutique

I bought the plugin yesterday and installed it following the instructions from plugin boutique. It installed and I can load it but no sound. It lights up when I press keys etc. just seems there is something Im missing and not being told so far.

Can someone please share how to get sound working on FL Studio 20. Im on a MAC 2009 10.13 OS

I searched youtube and google and nothing about this that worked for me. I tried reinstall, reloading FL. All my other plugins have sound.