Adding the App

From Nintex Automation (5.7) onwards there are two different apps for SharePoint. The legacy Nintex K2 for SharePoint: used for SharePoint on-premises and upgraded environments for SharePoint Online, and Nintex Automation for SharePoint: used on new installations for SharePoint Online.

Existing customers upgrading to Nintex Automation 5.7 use the legacy app from the SharePoint App Catalog for all SharePoint environments. New installations of Nintex Automation use the legacy app from the SharePoint App Catalog for SharePoint on-premises, and the new Nintex Automation for SharePoint app (SPFx) for SharePoint Online.

Legacy Nintex K2 for SharePoint app

Nintex Automation for SharePoint App for SharePoint Online