How to share WiFi password (if both users are in each other contacts)
- Make sure that your device (the one sharing the password) is unlocked and connected to the Wi-Fi network.
- Make sure you both have bluetooth on
- Select the Wi-Fi network on the device you want to connect.
- On your device, tap Share Password, then tap Done.
See more on from Apple: https://support.apple.com/en-us/HT209368
Or this youtube video: https://www.youtube.com/watch?v=NjPeuBVcMyg