Get account name in domain\username format in Nintex Workflow for O365

[krishnachaluvad]

Hi, we recently migrated from SP13 to SharePoint online. On SharePoint 13, we have a request form where user submit request to access to an application and that application accepts login name in domain\loginname format.

SharePoint 13/Nintex for SP13 easily provides the user account in "domain\loginname" format. After migrating to SharePoint Online, User Profile stores the account name in email format but not in domain\loginname format. I can ask user to provide their account name in "domain\loginname" format in the request or I can use Flow to get the "Nickname" property, wondering if there is a way with Nintex for Office 365? I also tried querying user profile using REST API, but no luck as it always stores in email format.