Good day!
I am sorry if I am writing on the place or wrong directory but I tried to visit your demo website (https://eark.essarch.org/accounts/login) and the instructions say that it is supposed to be signable under superuser login (with the same as the password) but whenever I tried it just do nothing.
It will not inform me about the wrong password and it will not redirect me anywhere nor say that the password/login is wrong. Could you please confirm if the demo website is still active or there is a login change?