How to write haredoc in pipeline

sisir

I want to run a set of ssh commands in staging server. I have put ssh commands in haredoc but the command shows invalid in validator. Can anyone help?

 

bitbucket-pipelines.yml

 

# This is a sample build configuration for PHP.
# Check our guides at https://confluence.atlassian.com/x/e8YWN for more examples.
# Only use spaces to indent your .yml configuration.
# -----
# You can specify a custom docker image from Docker Hub as your build environment.
image: samueldebruyn/debian-git

pipelines:
  default:
    - step:
        script:
          - apt-get update 
          - apt-get -qq install git-ftp
          - git ftp push --user $FTP_USER --passwd $FTP_PASS sftp://server.example.com/home/devmount/www/accounts.example.com/

          - ssh dev@server.example.com << EOF
    composer install
    php artisan migrate
    php artisan db:seed --class=UsersTableSeeder
EOF