Problem using SAML login for Storefront for first-time customer

Problem using SAML login for Storefront for first-time customer

I'm working on moving my store into Zoho Commerce, and have a SAML integration to my website already setup. I am running into a problem where the storefront won't allow a user to log in if they aren't already registered as a user in Zoho Commerce.

So the flow goes like this:
  1. First time user comes from my website over to the store. (They have not previously placed an order)
  2. User places item into cart.
  3. User begins checkout process.
  4. User clicks "Sign In / Sign Up".
  5. User is redirected to SAML login page.
  6. User enters their username/password and is authenticated by my website.
  7. User is returned to the storefront portal.
  8. Portal shows an error message: "New users should register before using the SAML Authentication. Please check with your administrator."
Obviously, the Storefront is assuming that anyone who logs in will already have a user entry in Zoho, but this is a problem when using SAML authentication because they technically do already have an account at my site; they shouldn't have to register for anything at the store. The system SHOULD create a user entry in Zoho when someone successfully authenticates via SAML if there is no existing user with that email address in the portal already.

So my main question is this: Is there a way via the Commerce API to create a user programmatically? There are ways to do this with other service APIs (Subscriptions for example), but I can't find any way to do this in the Commerce APIs.

If this were added to the API, I'd be able to programmatically create a user for them at the time they create an account on my website. Then, when they come over to the Zoho storefront, there's already a user entry for them, and they'd be able to log in successfully when placing their first order.