SDL TRADOS 2019 Prompsit plugin

Last week I bought an upgrade for Trados Studio 2019. I am unable to install the Prompsit plugin. SDL Trados 2014 is now removed from my computer. I can see Prompsit in the TM list but it doesn't work. Maybe it's an installation issue?
I've downloaded the plugin but if i try to open it, SDL Trados 2019 starts again the installation of the whole program.

Anyone can help someway? Thanks a lot!

Susanna