USPS shipping plugin documentation?

I purchased the USPS shipping plugin, but can't find any documentation re: the plugin configuration. There are some fields marked with an asterisk that are confusing -- User ID? Zip code -- is that for the origination location? Length/Width/Height -- why are these part of the config -- wouldn't they be order-specific?

Hello Brian,

Please submit a new ticket to send me the super admin account to your site so I can check and put the correct settings for UPS shipping plugin for you.

Sincerely, Giang

uh... no.
I don't want you to configure it for us. I want to understand what the various configuration settings are so we can configure it ourselves.