Hello,
I am in the process of developing a mobile app which helps small businesses to help with their inventory. In addition to this, I want to provide a payment gateway in my app so that this app can serve as a POS system.

To achieve this, what are my options? Do i need pay any price for incorporating their SDK/API? ( To be frank I don't even know the difference b/n these 2).


Thank You

I didn't find the right solution from the Internet.
References https://www.cnet.com/forums/discussions/incorporating-payment-gateway-into-mobile-app/


Example Transportation Management Video