Report Summery not showing

I am creating a Script Report. In that report, I am trying to add report_summary. First I am trying to add sample report_summary. But It shows black space. My code is -

from frappe import _, msgprint
import frappe
import datetime

def execute(filters=None):
	return get_columns(filters), get_data(filters), report_summary

def get_data(filters):
	conditions=get_conditions(filters)
	query = frappe.db.sql("""SELECT t1.lot_name, t2.item_code as 'Item', 
						ROUND(t2.amount, 2) as 'Purchase Amount', 
						ROUND(sum(t3.amount),2) as 'Sales Amount',
						CASE WHEN (sum(t3.amount) - t2.amount) <= 0 
						THEN '' ELSE 
						ROUND((sum(t3.amount) - t2.amount),2) END as 'Profit',
						CASE WHEN (t2.amount - sum(t3.amount)) <= 0 
						THEN '' ELSE 
						ROUND((t2.amount - sum(t3.amount)),2) END as 'Loss'
						FROM  `tabPurchase Order` as t1
						JOIN `tabPurchase Order Item` as t2 ON t1.name  = t2.parent 
						JOIN `tabSales Order Item` as t3 ON t1.lot_name = t3.lot_no 
						WHERE t3.docstatus = 1 AND t1.docstatus = 1 %s GROUP BY t1.lot_name, t2.item_code""" %(conditions), filters, as_list=1);
	return query

def get_conditions(filters):
	conditions = ""
	if filters.get("item_code"):
		conditions += " and t2.item_code = %(item_code)s"

	if filters.get("lot_name"):
		conditions += " and t1.lot_name = %(lot_name)s"

	if filters.date_from_filter and filters.date_to_filter:
		if filters.date_from_filter > filters.date_to_filter:
			frappe.throw("The 'From Date' ({}) must be before the 'To Date' ({})".format(filters.date_from_filter, filters.date_to_filter))

	if filters.date_from_filter == None:
		filters.date_from_filter = "2000-01-01"

	if filters.date_to_filter == None:
		filters.date_to_filter = frappe.datetime.get_today()
		
	conditions += " and t3.transaction_date BETWEEN '" + filters.date_from_filter + "' AND '" + filters.date_to_filter + "'"

	return conditions


def get_columns(filters):
	return [
		{
			'fieldname':'lot_name',
			'label': _('LOT No.'),
			'fieldtype':'Data',
			'width':'140'
		},
		{
			'fieldname':'item_code',
			'label': _('Item'),
			'fieldtype':'Data',
			'width':'140'
		},
		{
			'fieldname':'purchase_amount',
			'label': _('Purchase Amount'),
			'fieldtype':'Currency',
			'width':'150'
		},
		{
			'fieldname':'sales_amount',
			'label': _('Sales Amount'),
			'fieldtype':'Currency',
			'width':'150'
		},
		{
			'fieldname':'profit',
			'label': _('Profit'),
			'fieldtype':'Float',
			'width':'150'
		},
		{
			'fieldname':'loss',
			'label': _('Loss'),
			'fieldtype':'Float',
			'width':'200'
		}
	]

report_summary = [
    {"label":"cats","value":2287,'indicator':'Red'},
    {"label":"dogs","value":3647,'indicator':'Blue'}
]

Here is the output

If anyone face this issue and solved it, please help