CodeDeploy Error: Deployment group's ECS service must be configured for a CODE_DEPLOY deployment controller.

I've set up my ECS cluster with fargate and I've ran a successful deployment. However when attempting to set up a deployment group in CodeDeploy I receive the following error:

Deployment group's ECS service must be configured for a CODE_DEPLOY deployment controller.

From what I've read, this occurs because a blue/green deployment must be specified but I don't see that in the deployment group options. I would've expected to see it under 'Deployment settings'.