Retarget people with sticky bar who've already seen a popup


I am looking for a solution to “retarget” people who have already seen my popup.

Some context: I created a popup with a code. People see this popup after the 2nd visit on “the shopping bag” landing page. When people click on the code, it normally adds automatically to your shopping bag.
However, this code is only available when you have +50 euros in your shopping bag.

So if someone has a shopping bag of 40 euros, clicks on the code, he get’s a error message that states: “you need a shopping bag of 50 + euros”. The person goes back to the shopping pages and select 2 more products and now has a shopping bag of 55 euros. PROBLEM: the popup will not be shown again, so the code is lost.

My question is: how can I retarget these people with a sticky bar, with the code in? But only the people that has seen the popup.

Thank you!

Kind regards,

PS: I do not have access to the backend of the website + I am a junior in HTML CSS or JAVASCRIPT.