Welcome @karol.krak
I agree with everything @EmilyhNqpe says here! Contacting the administrators of the server you are working on is where to start.
The link on the homepage is for an email address. This reaches the administrators who can help to resolve a technical detail with the permissions.
Please let us know how this works out or if we can help more here! This forum is a great place to get help with using Galaxy but for the lower level configuration issues, we’ll need to point you to the people that run the server. 