Where to put "enablePlugins" in SBT? - sbt

Question

Following this tutorial, I am asked to add enablePlugins(WindowsPlugin) to my SBT configuration.
I did this by stating exactly this line in my build.sbt but all I get is "Cannot resolve symbol". Do I need to add the dependency somewhere?
Is this an auto plugin and can anyone explain to me what an auto plugin actually is and how I use it?
UPDATE: My build.sbt looks like that:
name := "ApplicationName"
version := "0.3-SNAPSHOT"
scalaVersion := "2.13.1"
enablePlugins(WindowsPlugin)
mainClass in assembly := Some("application.ConfigEditorApplication")
assemblyJarName in assembly := s"application-$version.jar"
assemblyMergeStrategy in assembly := {
case PathList("META-INF", xs#_*) => MergeStrategy.discard
case PathList("reference.conf") => MergeStrategy.concat
case x => MergeStrategy.first
}
libraryDependencies += "org.apache.commons" % "commons-lang3" % "3.9"
libraryDependencies += "commons-io" % "commons-io" % "2.6"
libraryDependencies += "ch.qos.logback" % "logback-classic" % "1.2.3"
libraryDependencies += "com.typesafe.scala-logging" % "scala-logging_2.13" % "3.9.2"
libraryDependencies += "com.typesafe.akka" %% "akka-actor-typed" % "2.6.3"
libraryDependencies += "org.scalatest" %% "scalatest" % "3.1.1" % "test"
libraryDependencies += "org.scalamock" %% "scalamock" % "4.4.0" % Test
libraryDependencies += "org.mockito" % "mockito-scala_2.13" % "1.11.3"
libraryDependencies += "org.mockito" % "mockito-scala-scalatest_2.13" % "1.11.3"

Answer 1

I found the solution to my problem: From the beginning, I suspected, that the plugin needs to be added before it can be enabled. Unfortunately, nothing of that sort was mentioned in the tutorial I was following.
The plugin which has to be added is the native-packager plugin: addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "1.7.0").

Answer 2

You should create your auto pluggin in your build.sbt. The build.sbt file must be at the root of your projet, at the same level with the file src.
You have information about it here and here.
In the page you mentioned they say you should set this in your build.sbt. Try this.
// general package information (can be scoped to Windows)
maintainer := "Josh Suereth <joshua.suereth#typesafe.com>"
packageSummary := "test-windows"
packageDescription := """Test Windows MSI."""
// wix build information
wixProductId := "ce07be71-510d-414a-92d4-dff47631848a"
wixProductUpgradeId := "4552fb0e-e257-4dbd-9ecb-dba9dbacf424"
UPDATE
Also, I found this question which is related to yours. It is true, it is an old one, but it might give you some hints. Some answers suggest performing updatings, others deleting and then reimporting the project.