Get Stripe customer ID via API

I am evaluating Invoice Ninja for our company, and have following situation:

A client makes a one-off purchase on our website via credit card (a new customer and payment intent are created, resulting finally in a charge), without using the Invoice Ninja Client Dashboard. Nonetheless the payment should be visible in Invoice Ninja.

When the purchase is done via the built-in Invoice Ninja Client Dashboard (via the “Buy Now” button feature), everything works automatically, and in the internal dashboard the button “View in Stripe” appears for this specific customer. Is there a way to do this “manually” via API?

The first problem I am facing is, when retrieving the client via for example GET <url>/api/v1/clients/10, there is no information about the Stripe customer ID (even though the customer has a Stripe button). Secondly, I would need to be able to update clients via API and attaching Stripe customer IDs to them. Is there another endpoint I am missing?

With the payments endpoint, it is possible to provide a transaction_reference item, this is also returned in the GET request. I was trying to find something similar in the clients endpoint for the customer ID …

Thanks for any hints!

Sorry, it isn’t supported

I see, thanks for the reply.
Another way I can think of: Is it somehow possible to charge a client via his Stripe credit card info?
I know that auto-billing is possible for recurring invoices, but how about a single invoice? Then, I wouldn’t need the Stripe customer ID, I would just tell IN to charge the default source.

TL,DR: Auto bill for single invoice?

Edit: A third way I could think of, is to pass a client_id parameter to the “buy now” button, as in:
<input type=“hidden” name=“client_id” value=“10”/>