library card to apple wallet

As Axel Foley said, your library would have to organise this.

Wallet, as Apple explains here, is for transactional cards and Apple gives the examples "...resort passes, boarding passes, movie tickets, coupons, rewards cards, and more."

However, there are apps of the Wallet type on the app store for other cards. I use one of these and it gives me the ability to store rewards cards, library cards and ID cards which can't be migrated to Wallet. Search on the App store and try a few on for size. Most of them are free or with In-app purchases if you want to keep using it.

Your Libray will have to provide this function. Generally this is done via an app from the App Store. Check with your library.

Axel F.