Handoff

Configure the activitycontinuation section of your AASA file so users can start an activity on one Apple device and continue it on another.

Handoff lets users start an activity on one Apple device and continue it on another. If your app supports Handoff between your website and your app, add your App ID in the Handoff section.

Xcode setup

Add the Associated Domains capability with activitycontinuation:your-domain.com.

Apple reference: Implementing Handoff in Your App