Is it possible with studio features or automated actions, to make it so that when clients purchase items in the PoS, a % of the spent money gets added to their eWallet? like a cashback program? or do I need to create a custom module from scratch to get a feature like this?
Yes! If you check at 7:37 when I mention the "Top-up eWallet" product, thats one that will appear in the shop which you can purchase to increase the amount you have stored in the eWallet :) After you validate payment and confirm the website order, the eWallet will increase by the amount purchased.