build release using signed key

app/build.gradle.kts

@@ -136,8 +136,18 @@ android {
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
 
+    signingConfigs {
+        create("release") {
+            storeFile = file("key.jks")
+            storePassword = System.getenv("KEYSTORE_PASSWORD")
+            keyAlias = System.getenv("KEY_ALIAS")
+            keyPassword = System.getenv("KEY_PASSWORD")
+        }
+    }
+
     buildTypes {
         release {
+            signingConfig = signingConfigs.getByName("release")
             isMinifyEnabled = false
             proguardFiles(
                 getDefaultProguardFile("proguard-android-optimize.txt"),