Enabling USPS shipping

[Azuremoonjewelry]

Hi!

 

I'm a "newbie", so please be kind! I am starting a new online business and have opted to use the USPS for shipping. However, when I access that shipping module of my site and click on USPS, it forwards me to a page/message stating that I am not authorized to change this information. I'm soooo confused! How do I enable the USPS option?

 

Dawn