The error you're encountering indicates that the APK you're trying to upload to the Google Play Console is not signed with the same certificate as the previous APK. This is a security measure to ensure that only the original developer can update an app.
To resolve this issue, you must use the same keystore and certificate that you used to sign the previous version of your app. Here are the steps to follow:
Locate the Original Keystore:
You need to locate the keystore file (usually with a .jks or .keystore extension) and the alias and password you used to sign the previous APK. If you can't find this information, it's crucial to retrieve it.
Build Your App with the Correct Keystore:
In your development environment, ensure that you are building your app using the same keystore, alias, and password as the previous version. This is usually configured in your app's build.gradle file.
Increment the Version Code:
As you mentioned, you've already changed the version code. Ensure that the version code in your app's build.gradle is indeed higher than the previous version you uploaded.
Generate a New APK:
Build a new APK with the updated version code using the same keystore.
Upload the New APK:
Go to the Google Play Console, select your app, and upload the new APK. Make sure you're using the same package name (com.namamisak.kumar1986.saket1) as before.
Save and Publish:
After successfully uploading the APK, save your changes and proceed with publishing your app update.
If you encounter any issues or errors during this process, double-check your keystore and alias information, as well as the version code in your app's build.gradle. Ensure that everything matches the previous version of your app that was published on Google Play.
Remember to keep your keystore file and its credentials secure, as losing access to it can result in being unable to update your app in the future.