Gatling object simulations not found import simulations

I am new to Gatling,
I downloaded the intellij, JDK8 and scala plugin and maven. Tried to run the gatiling script which is below
https://github.com/james-willett/gatling3-fundamentals/blob/master/src/test/scala/Engine.scala

But i am getting errors:

C:\gatling\gatling3-fundamentals\src\test\scala\Engine.scala:3:8
not found: object simulations
import simulations._

I put in import simulations but still getting error
code:
import io.gatling.app.Gatling
import io.gatling.core.config.GatlingPropertiesBuilder
import simulations._

object Engine extends App {

val props = new GatlingPropertiesBuilder()
.resourcesDirectory(IDEPathHelper.resourcesDirectory.toString)
.resultsDirectory(IDEPathHelper.resultsDirectory.toString)
.binariesDirectory(IDEPathHelper.mavenBinariesDirectory.toString)

Gatling.fromMap(props.build)
}

Can anyone help please.

Please check official material, such as: