Integrate Billing API

hi everybody,

i developed an app to sync/imports merchants data (such as users, orders etc..) on my system. I started the plublishing process but Shopify team blocked the process because i didn’t implement Billing Api.

Now i m stuck with some doubts.

First of al my organization provide 3 type of partnerships. Shopify team asked me to integrate those plans with their billing api.

I read Billing Api docs but i don’t understand how connect my external site with it.

Maybe i didn’t understand some steps but in docs i can see that after some charge action i should call shopify and start the billing process using xxxxxxxx.myshopify.com and X-Shopify-Access-Token. How can i generate them?

Do i have to create a shop specifically through which to manage the billing process?

Thank you