Creating a subscription thorugh susbcriptions api putting a past date as "starts_at" field does not generate invoice, how to generate?

Creating a subscription thorugh susbcriptions api putting a past date as "starts_at" field does not generate invoice, how to generate?

Hello,

Sometimes we need to create subscriptions through API (https://subscriptions.zoho.com/api/v1/subscriptions) setting a past date as "starts_at" field. But we noticed that in these cases no invoice is generated. We would need that subscription to generate an invoice (field child_invoice) in the same way as subscription with no "starts_at" field, which have the current date as default.

Is this possible, or how it could be the solution, via API, to have an invoice for a subscription with past date as "starts_at"?

Best regards