CLOSE POPUP UPSELLS

Hi we have one problem with upsells popoup!
How to remove or turn of X to exit popup, Becouse when i close popo up and i go do add to cart popoup is open again! People dont click continue to shopping when they see X to close popup..
Look image

https://ninainvalentin.si/izdelek/will-always-love-vecna-vrtnica/ u can test,, I just want ro remove or turn off X button for close popup

Regards
Zdenko