Docker Compose ECS Load Balancer not configured

I have a docker-compose.yml file like this:

version: "3"

x-aws-vpc: 'vpc-xxx'
x-aws-loadbalancer: 'arn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/xxx'

services:
  api:
    image: image/xxx
    restart: unless-stopped
    healthcheck:
      test: ["CMD-SHELL", "curl --fail http://localhost/health || exit 1"]
    environment:
      - PORT=80
      - REDIS_URL=redis://redis:6379
    env_file:
      - ./.env
    expose:
      - 80
    depends_on:
      - redis
    deploy:
      x-aws-autoscaling:
        min: 1
        max: 4
        cpu: 75
    networks:
      - alb

  redis:
    image: redis
    container_name: redis
    restart: unless-stopped
    expose:
      - 6379
    command: ["redis-server", "--appendonly", "yes"]
    networks:
      - alb

networks:
  alb:
    external: true
    name: "sg-xxx"

I created a load balancer myself so it would get created in specific subnets.

When I run the command docker compose up, the ECS cluster gets created correctly but there is no link created between the Load Balancer and the services. When updating the service, it says:

Elastic load balancing not configured. Load balancing settings can only be set on service creation.

I also tried to create a Target Group manually, but still nothing gets added to the targets.