After payment, the user's new service/product should be queued for creation

[Ahmadreza]

I have a WHM and I have connected it to WHMCS.

When users order a service and proceed to the payment gateway, after they make the payment, they return to the invoice page. However, since they have ordered a new service, the service creation process happens in the same request after the user returns to the invoice page. As a result, the page stays in a loading state for more than 20 seconds until the service is created, and only after that does the invoice page appear.

I want the service creation to be moved to a queue (either via a cron job or by creating a parallel request), so that immediately after payment, the user is returned to the invoice page.

How can I achieve this?