Would it be a security issue if I directly call the API from client (since no SDK available)?
Is it more work to call directly the API instead of using firebase functions with the SDK? As far as I understood it is just 3 calls, create billing plan, update billing plan and create billing agreement.
Do I need to create a billing plan all the time a customer wants to subscribe or is 1 enough (all customers get the same plan) and just make the billing agreement? If so can I use the checkout.js for only the agreement and create the billing plan manually?