android {
+    signingConfigs {
+       create("release") {
+            storeFile = file("keystore/release.keystore.jks")
+            storePassword = "ここに自分のkeystoreのpassword"
+            keyAlias = "keystoreを作った時のキーの名前、デフォルトだとkey0"
+            keyPassword = "ここに自分のpassword"
+        }
+    }

    buildTypes {
        release {
            isMinifyEnabled = false
            proguardFiles(
                getDefaultProguardFile("proguard-android-optimize.txt"),
                "proguard-rules.pro"
            )
+            signingConfig = signingConfigs.getByName("release")
        }
    }