SharePoint 2013 workflows aren't available for IRM policies in SharePoint Online or SharePoint Server on-premises
You create a Microsoft SharePoint 2013 workflow by using the SharePoint 2013 Workflow Platform content type on a list or a library in SharePoint Server 2013 on-premises or SharePoint Online. However, the workflow isn't visible in Information Rights Management (IRM) Retention Policy.
To work around this issue, use the SharePoint 2010 Workflow Platform content type when you create the workflow.
SharePoint 2010 workflow associations are the only kind of workflow that's surfaced by the IRM Retention Policy. The SPWorkflowAssociation class is the only class that's enumerated on the list or content type level that's displayed on the workflow drop-down menu.
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