services.dockeroperator Additional property attach is not allowed Docker Compose

I have below docker-compose.yaml

name: mydemo

    volumes:
      operator-volume:
        driver: local
    
    services:
      dockeroperator:
        build:
          dockerfile: .docker/Dockerfile
        volumes:
          - operator-volume:/terraform/dev
          - ./.kube:/root/.kube
          - ./utils:/operator/examples
        attach: false
        env_file: ".env"

when i am running docker-compose build , i am getting below error:

services.dockeroperator Additional property attach is not allowed

I have below docker version

Docker version 20.10.17, build 100c701