I've tested the process on my demo shop by manually adding the first snippet to my test shop's theme.liquid file. Then I created a custom pixel for my test shop with the second snippet.
I don't want to have to do that for every shop so I'm now trying to create an app that is simply a web pixel that will register listener events for the page_viewed & checkout_completed events.
My app has been rejected because of 3 things:
I don't have a screencast link showing how my app works
I don't have screenshots of my app
I don't have a functioning UI
I don't understand how my app is supposed to meet these requirements as there is no UI. There is only the web pixel. Below is a picture of the default page for the app that I thought would be sufficient but apparently it's not. Any advice on how to get my app approved? It won't be listed. I will send it to shops that sign up as affiliate partners so they will already know what the app will do.