How to get javascript to display a popup when clicked ?

Hello

i bought popup pro, and i would like to display a popup when a button is clicked.
I have put a button at the bottom right of my site ( https://www.sitepenalise.fr ) , ( bouton de test, under the logo ), but i have not been able to get the popup to be displayed.
Do you have precise instructions on how to do that ?
thank you