Lost your Wi-Fi connection? With Instant Hotspot, you can use the Personal Hotspot on your iPhone or iPad to connect your iMac to the internet instantly—no password required.
Note: Personal Hotspot requires an iPhone or cellular-model iPad, with iOS 8 (or later) or iPadOS. See the Apple Support article . (You don’t need to do anything on your device—iMac connects automatically.)
Tip: If you’re asked for a password, make sure your devices are set up correctly. See the Apple Support article Use an iPhone or iPad to connect to the Internet in the macOS User Guide.