The default username password is admin/admin
to configure the extension go to the EXT1 tab and make sure to put both NAT settings to YES:
Scroll down and add the proxy server
Display name and USER ID is the extension and password is the extension password
Scroll down again and add |*x. to the dialplan
Change the display name and change the voicemail number to *97.
Also, change line key to ext 1
In Regional section, Change the call pickup code. By default is *97 change it to something like *997. To see this option make sure you are in the advanced tab in the top right corner.
Scroll down and change the timezone to the correct one