In Clashub, under the Inventory and Marketplace tabs, you can view your Spark points. By opening the page of any Pow-UP you wish, you can explore the Spark module. Through this module, you can create Pow-UPs you don't have, and convert less used Pow-UPs into Spark points by burning them.
Additionally, in Clashub Journey, as you level up, or through special tournaments, you will have the chance to earn extra Spark points.