Sorry, I did a mistake.
This works only for the RUI (newclient) - not for the UI5.
The corrected link https://my<your tenant id>.crm.ondemand.com/sap/public/ap/ui/repository/SAP_BYD_UI/ HTML5/newclient.html?sap-ui-language=en&username=<your username>&password=<your password>
Best Regards,
Patric