• Open your repository
• Select Pipelines from the side menu
• Choose More > Other from the choice of languages
• Commit the default bitbucket-pipelines.yml file
• Select Settings from the side menu
• Select Environment variables from the PIPELINE section. See Using environment variables (First look at BitBucket Pipelines, part 3)
• Add the variables FTP_USERNAME, FTP_PASSWORD and FW_REINIT (these last two should be marked as Secured)
• Select Settings from the PIPELINE section
• Click View bitbucket-pipelines.yml
• Replace the default content with...

image: samueldebruyn/debian-git

pipelines:
  default:
    - step:
        script:
          - apt-get update
          - apt-get -qq install git-ftp

          - git ftp init --user $FTP_USERNAME --passwd $FTP_PASSWORD ftp://example.com/path/to/my/site/
          - curl https://example.com/?fwreinit=$FW_REINIT

• After the first run change init, which does an complete deploy, to push to deploy new updates/deletions to the ftp site