How do I change reward value in coding?

Hello,

opencart reward system is good but there is no option to change 1 Point = Value, ex. if I added 100 points to customer and customer use that point for purchase some product and product price is $200, then the customer will use 100 points and 1 point = $1 now customer get $100 discount, is this value can change from backend? if yes kindly help me

OC 2.2
https://karatsquare.com
thank you