Larry, I don't understand what you mean when you say you used your "Master Password". This plugin's name is misleading; it enables you to use your Zen Cart admin password to sign into any customer's account.

Regarding the missing "Place Order" button, I suggest you re-review the plugin's installation; I've got this version installed on a "vanilla" Zen Cart 1.5.5e site and can turn on/off the plugin's two configuration values and receive that button whenever the single admin ID matches my admin ID and/or when my admin profile is in the list of enabled profiles.