Why is the number of conversions in Google Analytics lower than the number of orders on my site?

Because ad and cookie blockers in your customers' browsers prevent tags like Google Analytics from working, you'll never have 100% of the conversion data sent to Google Analytics. This is why you'll always see a lower number of conversions in Google Analytics than the actual number of orders on your site.

If, on the other hand, you don't see any orders coming up in your Google Analytics account, we invite you to test your tag here to check its technical implementation and then find out what to do based on the result.