无法构建请求:没有在Gatling脚本中定义名为'token‘的属性

import io.gatling.core.Predef._
import io.gatling.http.Predef._
import scala.concurrent.duration._

class MySimulation extends Simulation {

  val httpProtocol = http
    .baseUrl("https://example.com")
    .acceptHeader("application/json")

  val scn = scenario("My Scenario")
    .exec(http("My Request")
      .get("/my-endpoint")
      .header("Authorization", "${token}")
      .check(status.is(200)))

  setUp(
    scn.inject(
      constantUsersPerSec(10) during (1 minute)
    )
  ).protocols(httpProtocol)
}