To be able to receive payment requests, you need to add an intent filter for the ginipay URL to your manifest. This also allows other Gini SDKs (e.g., Gini Health SDK) to detect if your app is installed:
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<data
android:host="payment"
android:scheme="ginipay" />
</intent-filter>
The intent filter can be added to the activity which will handle the payment flow of that payment request.