Follow these instructions for the settings required to establish a connection with the Estes Express API.
The Connection Settings page is used to establish the app’s connection to the Estes web service. Enter the information prompted for, then click Save Settings. After the settings have been saved, click the Test Connection button. You’ll see a success message if the app was able to establish a connection with the Estes servers. If the test failed, something about your connection settings information is incorrect. Make the necessary corrections and try again.

After you establish a successful connection, return to the User’s Guide for the app.

Estes Express API Connection Settings in Real Time Shipping Quotes app for Shopify

Nickname Enter a nickname for this connection. It is for your use only and will not be visible to visitors to your store.
Customer number Enter your Estes Express account number.
Username Enter the username you use to login into https://www.estes-express.com/
Password Enter the password associated with the username entered above.