The Privy Code is automatically installed on your BigCommerce store when you install the app, but in case it's not working, you can try these steps to install manually.
If you haven't already, install the Privy app for BigCommerce. Once it's installed, your screen should look like this:
From this page click on the account dropdown on the upper right, then "Business Settings".
From the settings page, on the left portion of the screen there will be a “Privy Code” link. Click that link and you will be presented with the following screen:
Copy the code that is displayed there and navigate to the Storefront design section of your BigCommerce dashboard.
Under Storefront, click on Footer Scripts. Paste the code that you’ve copied from the Privy settings into the Footer Scripts section displayed on your screen and click Save.
Privy is now installed on your BigCommerce store!