Navigate to Facebook Business Events Manager. You can access it directly using this link: https://www.facebook.com/events_manager.

In the Events Manager, you will see a list of your available Pixels (if you've already created one). If you haven't created a Pixel yet, click on the green "Connect Data Sources" button, select "Web," and then click "Get Started." Follow the instructions to create a new Facebook Pixel.

Once you have a Pixel, click on its name in the list. You'll be taken to the Pixel's overview page.

On the Pixel overview page, you can find your Facebook Pixel ID in the top-left corner, under the Pixel name. It's a 15-16 digit number.

Copy and Paste your Facebook Pixel ID into UpStackified Facebook Integration

Click Create or Update Configuration

Find out How to Generate your Facebook Ads Conversion API Key

Check out this article to find more information about setting up Shopify Multiple Facebook Pixels with UpStackified Shopify App