any reason why I cant put a service inside an existing cluster

let lb = new awsx.elasticloadbalancingv2.ApplicationTargetGroup(
  "scolasticua_api_tg",
  { port: 80 }
).createListener("scolasticua_api_ls", { port: 80 });
let cluster = aws.ecs.getCluster({ clusterName: "tyc00n-fb4c62c" });
let service = new awsx.ecs.FargateService("scolasticus_api", {
  desiredCount: 2,
  taskDefinitionArgs: {
    containers: {
      scolasticus_api: {
        image:
          "scolasticus_api:latest",
        memory: 512,
        portMappings: [lb]
      }
    }
  },
  cluster: cluster
});