Congrats!
Can you elaborate on the 'wallet on the phone' please?
We have Samsung phones. I was able to create a folder on on one of the Home screens with photos of our vaccination cards so we could find them quickly. Take photos of front and back of cards, open Samsung My Files app, select either Internal or SD card, create a new folder, give it a name that is easy to find. Open Gallery app, select card photos, copy to the folder you just created. Switch back to My Files, long press on the folder you just created until options appear, select More options, select Add to Home Screen. the folder should not appear on your Home screen. You can then move it to a convenient location or screen with a long press on the folder.
Thanks! Hope you have a great trip!