it says “there was a billing problem with a previous purchase” yet i’m not trying to buy anything. just update an app?

Hi

It sounds like you're unable to update apps. We're happy to provide some information. If there is a billing problem with a previous purchase, you won't be able to download or update existing apps until that issue is resolved.

We see you came from the following article, which is the best resource for resolving the issue at hand: If your payment method is declined in the App Store or iTunes Store - Apple Support

If you continue to have trouble, we suggest you contact Apple Support.

Have a great day!