Cannot add card to Apple Pay

I reset my phone a couple of months ago to try and fix some niggling issues. One of the things that was blown out was my Apple Pay card. I tried to add it back in this morning and it tells me I need to update my iOS in order to add that card. I tried two different cards, same thing. One of them had been in the phone before, but they sent me a new tap card so the code and expiration are different than the original one.

I am still running iOS 12.x on a 2016 SE

Did everyones Apple Pay cards get deactivated in the last couple of months if you are on an older iOS, or is it just adding them that can’t be done?

I was all set to get a 12 Mini but am holding out for the 13 Mini and really paying for it!

Thanks
Diane