You can display a Popup for visitors from the referrer domain using the Post Grid Combo plugin. This article will help you to display a popup for visitors from the referrer domain.
To begin, insert a “Popup” block.
Click on the Visibility Tab and click on the Add Group button.
Then Click on the Add Condition Button to add a condition to load the Popup.
Here, choose the Referrer Exist option to make the popup display for visitors from the referrer domain.