Ushahidi default username/password admin/admin not working


I have installed Ushahidi on ubuntu 18.04 following this guide:

Accessing the API returns the default API response:


When I access the client URL, I can not log in with the default username admin and its password admin or administrator. The login button only becomes active when you provide an email as a username. What am I doing wrong? I can still sign up and log in with the created normal username and password. I need administrator privilege to use Ushahidi.

Any help would be much appreciated.

Thanks in advance.