Not able to create background job

Hello,
I want to add background job. But somehow it is not coming in background job page & hence it is not working.

import frappe

def message():
	frappe.msgprint("Inside")
	print("Completed Schedule Task.")

@frappe.whitelist()
def on_submit(docname,time):
	# Calculate the delay in seconds between now and the schedule_date_time
	schedule_time = datetime.strptime(time, '%Y-%m-%d %H:%M:%S')
	one_day_earlier = schedule_time - timedelta(days=1)
	hours = one_day_earlier.hour
	minutes = one_day_earlier.minute
	now = now_datetime()
	delay = (schedule_time - now).total_seconds()
	if delay > 0:
		frappe.enqueue(
				message,
				now=False,
				queue="default",
				timeout=delay,
				enqueue_after_commit=True,
				at_front=True
			)
		frappe.msgprint("Started")