Hey AJ!
Just to add to this, your actual voicemail will not work until you assign an internal extension for voicemail in the voicemail portal like you mentioned (calling-locations-voice portal). But I also found out something interesting: if you want to dial the voicemail pilot, if you just dial the number you place here in the webex calling voice portal, it won't log you in to your actual voicemail!
To login to your actual voicemail, enter your extension itself, it will take you straight to the voicemail pilot
