Developing an app to accompany our website, worried that we would lose people in the transition if they couldn't remember their password, we were looking to make our app do Password AutoFill, a feature in iOS.
A talk from WWDC introducing the feature: https://developer.apple.com/videos/play/wwdc2017/206/
It works well, but there were a few bumps in the road making it work for React Native on Expo, so here are some notes to help out.
Apple's docs are here: https://developer.apple.com/documentation/security/password_autofill and they say something like this: