BaseSimulation is not recognized

Hi, I'm trying to use IntelliJ for Scala development. I'm new to IntelliJ.
I installed IntelliJ IDEA Community Edition.
I installed the Scala SDK.
I also instellaed the Scala Plugin for IntelliJ.
Next, I imported a project, which main class looks like:

import io.gatling.core.Predef._
import io.gatling.http.Predef._

class MyFirstTest extends Simulation {
(...)

If I try to build it, I get an error "not found: type BaseSimulation"

import baseConfig.BaseSimulation
^

When I hover the mouse over that code, I see a bulb icon, If I click on it, it suggests to "Set Up Scala SDK" (which I actually already did), but it shows an empty "Use library" list to choose from. An error message displays "Error: library is not specified"

I read someplace, changing the org-scala-lan dependency version in build.gradle from 2.11.8 to 3.2.1 would fix the error, but it didn't.
Do you have any suggestion?

Thanks in advance