You uploaded an APK with an invalid signature (learn more about signing). Error from apksigner

I am facing a Google play store registration issue:

We have registered a mobile app

And it is a beta version.

I tried to update recently.

The console gives an error

Your app currently targets API level 29 and must target at least API level 30 to ensure it is built on the latest APIs optimized for security and performance. Change your app’s target API level to at least 30

I tried with a config file setting to reflect the version to be 30. ( config.xml ) I have given the parameter for your reference.

And also an additional change was made in build.gradle file

build.gradle file :

allprojects {
apply from: ‘repositories.gradle’
repositories repos
//This replaces project.properties w.r.t. build settings
    project.ext {
    defaultBuildToolsVersion="30" //String
    defaultMinSdkVersion=25 //Integer - Minimum requirement is Android 5.1
    defaultTargetSdkVersion=30 //Integer - We ALWAYS target the latest by default
    defaultCompileSdkVersion=30 //Integer - We ALWAYS compile with the latest by default
    }
}

The build was successful but facing a new error. Created a new APK and when tried to update play store got an error

You uploaded an APK with an invalid signature (learn more about signing). Error from apksigner: ERROR: MIN_SIG_SCHEME_FOR_TARGET_SDK_NOT_MET: Target SDK version 30 requires a minimum of signature scheme v2; the APK is not signed with this or a later signature scheme

As I am stuck, So please any pointers to resolve this issue is highly appreciated.

I am attaching the additional details.

Ionic:

Ionic CLI : 6.16.3 (C:\Users\User\AppData\Roaming\npm\node_modules@ionic\cli)
Ionic Framework : @ionic/angular 5.6.13
@angular-devkit/build-angular : 12.1.4
@angular-devkit/schematics : 12.2.0
@angular/cli : 12.1.4
@ionic/angular-toolkit : 4.0.0

Cordova:

Cordova CLI : 10.0.0
Cordova Platforms : android 9.1.0
Cordova Plugins : not available

Utility:

cordova-res : 0.15.3
native-run : 1.1.0

System:

Android SDK Tools : 26.1.1 (C:\Users\User\AppData\Local\Android\Sdk)
NodeJS : v14.15.0 (C:\Program Files\nodejs\node.exe)
npm : 7.20.3
OS : Windows 10