chmod: missing operand after ‘og=’ Gitlab CI/CD executor=shell-CodePudding

I have the following in .gitlab-ci.yml for pipeline for development server:

   stages:
    - deploy

   deploy to dev:
    stage: deploy
    tags:
      - development
    script:
      - chmod og= $ID_RSA_DEVELOPMENT
      - apk update && apk add openssh-client
      - ssh -i $ID_RSA_DEVELOPMENT -o StrictHostKeyChecking=no $SERVER_USER@$SERVER_IP_DEVELOPMENT "cd /home/deployer/folder-name && bash dev.sh"
    environment:
      name: development
      url: http://{IP Address}
    only:
      - dev

This pipeline is triggered by pushing to dev branch. The pipeline for production seems to working fine with the same code with