I was unable to find and create the SharePoint 2013 workflow
using SharePoint designer for office 365 SharePoint site and I got the
following message that “The option for
the SharePoint 2013 workflow platform is not available because the workflow
service is not configured on the server. Please contact your server
administrator”
Finally found that reference link and it says that
have to enable “Preview features” in SharePoint online Admin center setting
page and it worked for me J
