Hey everyone,
I’m currently working on a Shopify app that lets me earn a commission on sales generated through my website.
Does anyone know how I can implement a “billing per usage” model for this? Any references or tips would be super helpful!
Thanks a lot! 
if you’re using the Shopify remix application structure/system. you might be able to use their billing API the most recent one is v3.
https://shopify.dev/docs/api/shopify-app-remix/v3/apis/billing
there is a specific “createUsageRecord” that might work for you I’m not exactly sure if that’s exactly what you want but maybe that will help.
good luck!