For simply submitting the ticket - If I remember correctly, you will want to POST to:
/api/v1.0/tickets-templates/{ticket template id}/new-ticket
I don’t think you need a payload either as that info is all defined within your template.
My understand of the flow is that the “Workflow Details” section of your template is a one-time “rule” that fires specifically for that template. Since you are leaving that action blank, you may have to get creative with some additional API calls that run after ticket submission. We’ve done this by pulling the TicketId from the response after submitting the ticket, from there you can set location, requestor, etc with the different endpoints.