Linking app through Digital Asset Link protocol

Question

My problem is that uploading my signed APK for my android instant app to google play console gives me the following error:

Your site 'anam-instant.mybluemix.net' has not been linked through the Digital Assets Link protocol to your app. Please link your site through the Digital Assets Link protocol to your app.

I have a single base module, with the AndroidManifest.xml intent filter as follows:

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
        <intent-filter
            android:autoVerify="true"
            android:order="1" >
            <action android:name="android.intent.action.VIEW" />

            <category android:name="android.intent.category.BROWSABLE" />
            <category android:name="android.intent.category.DEFAULT" />

            <data android:scheme="https" />
            <data android:scheme="http" />
            <data android:host="MYURL.net" />
            <data android:pathPrefix="/hello" />

        </intent-filter>
        <meta-data
            android:name="default-url"
            android:value="https://MYURL.net/hello"/>

At /.well-known/assetlinks.json

[
    {
        relation: [
            "delegate_permission/common.handle_all_urls"
        ],
target: {
    namespace: "android_app",
    package_name: "com.example.anam.my_instantapp",
    sha256_cert_fingerprints: ["SHA256-CERT"]
        }
    }
]

I have Google app signing enabled and got my sha256 cert from there, using the Upload certificate.

I have verified that the package name is the same as the package name in the base module's AndroidManifest.xml.

I have verified that my robots.txt allows all.

I'm trying to release this under Instant app development.