I'm using an external payment gateway for my store and I suspect that I'm losing a fraction of customers after they click on the Complete Order button (and then are subsequently redirected to the payment gateway secure page). Unfortunately, the payment gateway doesn't have tracking for this. Shopify doesn't track those outbound clicks either, nor does Google Analytics.
One more thing to add, though. The Complete Order Button code has this trekkie, but I don't know if the data gathered with it is accessible anywhere using the Shopify's standard analytics means,
Question: How do you track those clicks? I'm on a Shopify plan, so I don't have access to checkout.liquid. If someone could point out to where or how I can see whether a user clicks on the Complete Order button, it would certainly make my day.