Help! Which Apis should I use for my project?

Hi guys,

We are updating a digital product (written in Javascript, html and css) to be activated with a monthly subscription. Which APIs should I call in the code?
I would like to know if a customer has an active monthly subscription and one day a month the product asks if the subscription is active on the platform.

Help

For monthly, you can use the RecurringApplicationCharge (shopify.dev) API.

Use the POST to create the charge and a mechanism for the merchant to be redirected to the charge acceptance screen.

Use the GET to check for the charge status periodically

Hope that helps, all the best.

How do I use the user’s username and password in the request API to get that information?

You don’t, you use the access token provided from the store that installs the app, see Authentication and authorization (shopify.dev)