1.  to have a signed certifcate (https) on your instance
    
2.  open {BASE\_URL}/admin/settings/experimental
    
3.  enable "Built in OAuth applications" flag
    
4.  open {BASE\_URL}/admin/oauth/applications
    
5.  enable "Built-in OAuth applications" there
    
6.  log in inside the app  
      
    NOTE: from version 17.0, the flag "Built in OAuth applications" is not in experimental any more