Getting an Input Exception for invalid quantity when trying to modify SLL order placement.

Error -
kiteconnect.exceptions.InputException: Invalid `quantity`.

Code -
# Code for creating order params
def create_modify_SL_order_params(ord_id, price, trigger_price):
modified_SL_order_param = {
"variety": "regular",
"order_id": ord_id,
"price": price,
"trigger_price": trigger_price
}
return modified_SL_order_param

This code is generating the required order params which is getting printed on the console for passing it to the modify SL order function which has the following code.

def modifySLOrder(order_params):

order_id = kite.modify_order(price=order_params['price'],
trigger_price=order_params['trigger_price'],
order_id=order_params['order_id'],
variety=order_params['variety'])
return order_id

Expectation -
This is the first time I am facing this issue and the code had been running without any issues till today. Find it surprising that there is an input exception for quantity which I understand is an optional argument.