In-App Update API showing UPDATE_NOT_AVAILABLE while testing on debugging device

As of today, in-app-update testing can not be done for a debug build. You don't need to put your apk to PlayStore to test also. The best way to test in-app-update is by using internal-app-sharing.

If you follow the below steps one-by-one, you'll be able to test successfully.

1. To test the app, a tester has to first enable Internal-App-Sharing in PlayStore, follow this link for the same, How to Enable Internal App Sharing for Android?
2. If you're brave enough to understand the official documents, then simply follow this link to set-up in-app-update testing in your device, https://developer.android.com/guide/playcore/in-app-updates#internal-app-sharing

Here, I'll be writing the same in easy words.

Once you're done with setting up internal-app-sharing in Play-Store, make sure that you have to upload 2 apks to internal-app-sharing on Play-Console and hence generate 2 links. Both apks will be signed using the same signing-key (need not be the same as the one you use to sign for production, any dummy signing-key would work).

3. First you upload an apk with in-app-update implementation with lower VersionCode (say, 100) to internal-app-sharing on play console.

To know, How to upload apk to internal-app-sharing on Play-Console, follow this lisk, https://support.google.com/googleplay/android-developer/answer/9844679?visit_id=637437125318137239-1277036129&rd=1

NOTE: make sure, you have uninstalled any preinstalled app with the same package-name in your device.

4. Now you copy the link of the app you uploaded to internal-app-sharing on the play console and use this link to install the app on your device.

NOTE: Before installing, make sure the email-id you're using on play-store has been added in the mail-list on internal-app-sharing on play-console.

5. Now, once you've installed the app using the link. Now, you need to again create a new signed apk with higher VersionCode (say, 101). And upload this apk to internal-app-sharing.

6. Now, copy the link with higher VersionCode from internal-app-sharing. Click on this link on your device, it will take you to play-store but this time, update button will be enabled rather than install button as app is already installed in your device with lower VersionCode.

7. You don't have to click the update button on PlayStore. You just have to click the link and hence open the screen on PlayStore. Now close PlayStore app.

8. Now, you can launch the already installed app from your device.

If your implementation of in-app-update is fine, launching the app would appear the dialog from PlayStore for update.

Lastly, don't forget to upvote if it helps you in any way. Keep Coding!

I struggled with this same problem for a few days before once again going through the documentation thoroughly. Read this section on the official documentation of the in-app updates.

The link describes the correct testing procedure as follows:

1. On your test device, make sure you've already installed a version of your app that meets the following requirements:

• The app was installed using an internal app sharing URL
• Supports in-app updates
• Uses a version code that's lower than the updated version of your app

2. Follow the Play Console instructions on how to share your app internally. Make sure you upload a version of your app that uses a version code that's higher than the one you have already installed on the test device.
3. On the test device, only click the internal app-sharing link for the updated version of your app. Do not install the app from the Google Play Store page you see after clicking the link.
4. Open the app from the device's app drawer or home screen. The update should now be available to your app, and you can test your implementation of in-app updates.

This is also super helpful because you don't have to wait for the app to be published, you can start testing immediately.

I had the similar issue of having UPDATE_NOT_AVAILABLE. After hours of researching, here is how i solved:

1. use Google play store to install a version of the testing app (I used internal test track rollout)

2. rollout another version with higher VERSION CODE on Play Console (the same internal test track)

3. close both testing app and Google play store (not just back to home, use recent key and swipe them off)

4. open the Google play store and ensure that testing app has an update available (you can check it under "My Apps & Game" > Installed)

5. now open the testing app and check for UPDATE_AVAILABLE

This works for me almost immediately after rollout