Two halves. The second belongs to whoever builds your app. See the step-by-step guide in
Open links in your app.
On Onelink.to:
- Set up your custom domain, if you have not already
- Open Settings > Custom Domains and expand the domain
- Under Open in app, upload the association file for each platform — we check it and point out anything that looks wrong
In your app:
- iOS: an Associated Domains entitlement for
applinks:app.example.com — Supporting associated domains. To test without waiting for Apple's CDN, append ?mode=developer and enable Developer Mode on the device - Android: an intent filter for the domain with
android:autoVerify="true" — Verify Android App Links. The fingerprint must be the SHA-256 of the Play App Signing certificate, not the upload key — Play App Signing. Check a device with adb shell pm verify-app-links --re-verify your.package.name
Both need a new build submitted to the stores, so plan this with your app release.