Javascript for Matomo Event when submitting

Hello

I’m using the WPforms. We use Matomo for analytics and I’d like to trigger an event whenever a user submits the small form. I’m not sure how and where to add the javascript. From my understanding I can:
1. add the javascript that triggers the event with a snippet plugin
2. somehow this script has to be triggered when a user submits. However I’m not sure how to do this.

Help would be much appreciated.

Infos:
WPforms Plugin: Version 1.6.1
Wordpress Theme: Twentyseventeen (Version: 2.3)
Wordpress: Version 5.4.2