Field names not working for RootID in Filteration step

I am trying to test your app in an office 365 environment. When I go to step 2 of the configuration steps for the org chart it asks for a RootID. I first thought this was the root site for the office 365 environment but none of the sites worked. I then tried to use one of the user profile fields as the rootID. That still does not work. Please let me know of an example that I can try for RootID.

Hi,

Root ID is and ID of root employee in your case. Office 365 version of Org Chart uses user profiles as a data source. So, you need to specify an account name of employee who will be displayed in the root of your hierarchy. For example account name of CEO.

On-Premises versions doesn’t require filling this field, possibly we will add automatic root detection to SharePoint Online version also.