How get Targets API level 29 to target at least API level 30

When I try to update APK in google play console its showing 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
After that, I will change in config.xml file and also change 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
}
}

And create a new APK and try to update in google play console, this time its showing 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
Problew is not solved, I am stuck, So pllease help me out from this situation, thank you

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