On iPhones that support background tag reading, the system scans for and reads NFC data without requiring users to scan tags using an app. The system displays a pop-up notification .Add support for background tag reading to your app by turning on Associated Domains under the project’s Capabilities tab. This step adds the Associated Domains Entitlement to your project’s entitlement file and to the app ID. Next, enter the domain for each universal link supported by .