1. Log into your PaidShipping account.
2. On the left-hand side, select Integrations.
3. Click on the option for New Integration.
4. Place the mouse cursor over the OpenCart logo, and then click on the Plus sign.
5. Enter a Store Name.
6. Use Click here option to download the appropriate bridge connector plugin for your OpenCart version ( your version can be found in the footer of your OpenCart admin Dashboard page)
7. Next, in a new tab, login to your OpenCart admin page.
8. On the left-hand side of the screen, select Extensions.
9. Now select Installer.
10. Click the Upload button and upload the bridge connector  (You should see a message that says "Success: You have modified extensions!")
11. On the left-hand side of the screen, select Extensions. (under Installer)
12. Click the dropdown and select Modules.
13. Locate the extension named Bridge Connector and click the green + icon on the right-hand side. (You should see a message that says "Success: You have modified modules!")
14. Click the blue Edit icon next to Bridge Connector on the right-hand side.
15. Select the Store Key and copy it.
16. In the PaidShipping tab of your browser, paste the Store key into the appropriate field.
17. Copy your Store URL and paste it into the PaidShipping tab in the appropriate field (your store URL can be found in your OpenCart dashboard by clicking the System menu on the left-hand side, then clicking Settings).
18. Add the name you wish to use for your store in  PaidShipping in the Your Store Name field.
19. Click the Connect button.