Hello there and welcome to the Wowza support forum.
You can check what the password and user name are in the admin.password file located in [install-dir]/conf/admin.password.
It will look like this:
The admin.password file is looks like this:
# Admin password file (format [username][space][password][space][group])
#username password group|group
For the "group" entry use "admin|advUser"
user pass admin|advUser