Migrated to kotlin on the app folder. Broken build

build.gradle

@@ -1,7 +1,7 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    ext.kotlin_version = '1.2.71'
+    ext.kotlin_version = "1.3.72"
 
     repositories {
         google()
@@ -9,10 +9,13 @@ buildscript {
 
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.2.1'
+        classpath 'com.android.tools.build:gradle:4.0.0'
         classpath 'com.google.gms:google-services:4.0.1'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
+        def nav_version = "2.1.0-alpha06"
+        classpath "androidx.navigation:navigation-safe-args-gradle-plugin:$nav_version"
+
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }