Pop up on 1) click + 2) session start?

[SuatB]

Someone asked almost the same question
This person only wanted to do it on the frontpage, but you could add the interaction on a part of the footer, and it would be sitewide.

Popup Limits Content loaded "Run only once"

I would like to have a popup which will be shown on the homepage after the content is loaded. After you visit different sites the popup only should be shown after clicking on a specific button. I found this topic but in this case the popup shows after the mouse leaves the window and in this interaction you can set “Run ony once”. How can I achieve to show the popup automatically only on the homepage after the content is loaded and on all other sites only when a button is clicked?

Hope this Helps
Cheers Suat