frontend form action: save as draft or publish
I believe you're looking for entryRevisions/publishDraft:

&lt;input type="hidden" name="action" value="entryRevisions/publishDraft"&gt;


You can see the specific inputs it is looking for here: https://github.com/craftcms/cms/tree/master-v2/src/controllers/EntryRevisionsController.php#L188