In Spent Rule in Credit Settings, You can set credits to be used by customers based on their cart value range. So that you can limit your customers usage of their total credits or permit to use total credits.
Go to GET STARTED -> Manager Settings OR
Sidebar Menu -> Settings
Click on "VIEW" in the block "Reward/Credit Settings".
There enable store credit and SAVE
Reward settings block will open, there click on spent rule
By doing the above settings,
Customer able to enter their choice of reward points out of their total reward points at cart page
On click CHECK OUT button, discount will apply