You should be able to generate the token from the Get Token URL on the http://mydomain/arcgis/rest/services/ page. Upper right corner next to Login.
I normally use Request IP for the Client parameter. If you have the credentials correct, you should see a long alpha-numeric string of characters, the token.
In your browser, after appending that to your service endpoint url using ?token=, where it used to say Login, you should now see "Logged in " along with the domain\username of the credentials you used to get the token.
If you have any secured services, and the account you used for the token has access to those secured services, you should now be able to see them listed in the folders.
If not, you might have some things left to configure.
Using https can be especially troublesome if you don't have the certificate/domain name configured correctly, or if you are entering them in an manner that is not consistent with your certificate.