Hi
you seem to be a little confused here and are trying to log in to a Xerte installation which belongs to another University. Xerte Online Toolkits is a free and open source web server application which you can download and install on your own web server. You can download by following the download links here on the community site
xerte.org.uk
Typically your university IT team would need to install it on a web server for you and anyone else in your organisation to use.
If you need external hosting or help with internal hosting there are a few of us in the community who offer this as a service but your first point of call should be your internal IT team.
HTH
Ron