It looks like your colleague does not have the right permission to use this "Workflow".
To grant it, go to Settings -> Permissions -> (Select user group where your colleague is) -> Workflows
Once here, we can decide the type of access we would like for the selected User Group, as well as which workflows this access is for.
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*Don't forget to save your changes. *
It is important to note that the "All Users" group includes all of our users, be mindful of the settings here.