1. In build.sbt, import the plugin
import au.com.dius.pact.provider.sbt._

SbtProviderPlugin.config ++ Seq(
  providers := Seq(
    ProviderConfig(name = "Provider", port=49600, requestFilter = Some(request =>
      request.addHeader("Authorization", "Bearer NTY5YjQwNGQtYjFkMi00N2UyLThiODgtYzQzNzBkNzlkMDQ5")
    )).hasPactWith(ConsumerConfig(name = "TestConsumer", pactFile = file("spec/pacts/test-consumer.json")))
  )
)

2. In a Makefile, have the following task:

run-provider:
   make run-app & \
   sleep 60
   sbt pactVerify

Where run-app is another Makefile task to spin up the app:

./activator "project test-server" ~run

We spin up the project, and then & will put it running in the background. We wait for 60 seconds for the project to be up. Finally we run Pact Provider.