Magento 2 Reward Points extension allows your clients to obtain points soon after any transaction is done. However, they must get all needed conditions related to shopping cart and catalog you set up in the earning points rule.
The rule is founded on subtotal, quantity items in cart, billing, shipping address, categories, SKU,... and each rule will be assigned to specific customer groups as well as stores. One group/ store is applied one or more earning rules which are active depending on their priority. Especially, you should offer the expiration of reward points in order to promote the users to spend more.