def METHOD_NAME(self):
    order_form = Form(self.env["sale.order"])
    order_form.partner_id = self.partner
    with order_form.order_line.new() as line_form:
        line_form.product_id = self.product
        line_form.product_uom_qty = 1
    sale = order_form.save()
    if self.carrier:
        delivery_wizard = Form(
            self.env["choose.delivery.carrier"].with_context(
                {"default_order_id": sale.id, "default_carrier_id": self.carrier.id}
            )
        ).save()
        delivery_wizard.button_confirm()
    sale.action_confirm()
    return sale