Android instant app deeplink with custom scheme: UNKNOWN_URL_SCHEME

Question

I have an SDK that registers an Activity to handle a custom scheme, at some point the SDK would open a http url to my website, upon clicking a button in the website, a user will be redirect to customscheme://scheme_host_url/their_application_id - which would close the browser and redirect back to the user's native app using the SDK by opening CustomSchemeHandlingActivity

However if an instant app uses my SDK, this would not work, they will just see net:UNKNOWN_URL_SCHEME in their browser. I think this is expected, as instant app doesn't really have my SDK and CustomSchemeHandlingActivity installed locally.

Is it expected that this just won't work for Android instant app?

<activity
    android:name=".CustomSchemeHandlingActivity">
    <intent-filter>
        ...
        <data
            android:scheme="customscheme"
            android:host="scheme_host_url"
            android:path="/${applicationId}" />
    </intent-filter>
</activity>

Answer 1

Instant Apps only work with App Links, and as you already know this means that you can only use https urls.

https://developer.android.com/training/app-links/instant-app-links