Trying to Update Apps, but there’s no prompted continue button?

I’ve been trying for a few days now to update apps on my iPad 2 Air (iOS 11.2.6) but whenever I open the app store and tap the update button, it tells me “Verification Required” and to tap Continue to verify my billing information. First of all, these are all free apps and shouldn’t require billing information to update (I‘ve turned off the payment information from my AppleID settings), but secondly, and most importantly, the only button it gives me to tap is an “okay” button, not cancel, not continue. Tapping this okay button does nothing. I’ve restarted the apps and my iPad countless times. I cannot update my apps. This iPad functions as a work computer and is anchored in place to a cash drawer as well, so there’s no syncing it to a computer or anything to get around this. Please help! I need to update my POS system so I can sell my merch!