Welcome to the Shopify Community! Happy to look into some app options with you. One in particular I've found that sounds like it will suit your needs is called Geolocation Warnings & Pop Ups. You can even show custom pop ups based on the customer's country.
One other similar option is Ultimate Product Warning. Outside of this, there are lots of pop up apps available, as you may have noticed. Most of these are to do with sales promotion, email collection, discounts, etc. You can find these by searching "pop up" on the Shopify App Store.
Let me know if either of these apps will solve your issue! If not, please provide more context and specific examples so we can keep looking together.
Hilary | Community Moderator @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog