This documentation platform covers only major versions of the Umbraco Workflow since Umbraco 9+. If you are using Umbraco Plumber, you will need to go elsewhere.
The documentation for Umbraco 7 and 8 lives on our.umbraco.com.
Umbraco 11 Documentation | https://github.com/umbraco/UmbracoDocs/tree/umbraco-eol-versions/11/umbraco-workflow |
Umbraco 8 Documentation | https://our.umbraco.com/documentation/Add-ons/Umbraco-Plumber/ |