PlayIt Manager does not have a default password as, by default, it does not require a password until you set one via the Settings > Security page.
You can prevent being asked for a password when connecting locally by changing the RequireAdministratorPasswordLocal attribute value to false in the C:\ProgramData\PlayIt Manager\settings.xml file.
You will need to stop PlayIt Manager by right clicking the Manager icon on the notification area and restarting it to pick up the change.
I am trying to demo playitlive and playit manager but playit manager is asking for a password for Administrator.
Is there a default password