How to use API plugin for integration

Hello,

I need to make any kind of integration (does not matter of the level, it can be very simple) of a loyalty and promotion, its name is Boxplosive, with NopCommerce. Because I am not familiar with plugins and APIs, can you tell me or explain me how can I use the available API plugin and probably the MailChimp Synchronization plugin. I have seen they are for free and I installed them at the NopCommerce. I have read the description of the API plugin that I have an access to Customers like an object, but I don't know how I can implement the integration with the customers, connected to Boxplosive for instance. Or you might probably can have any other idea for integration between both systems, I am intrigued to read your brainstorm. I would be very happy if someone can help me, because I am not familiar, working with that and I don't have almost any experience.

P.S: If you have any other idea for integration without plugin, I am open to share it :)!

Best regards!

Please don't duplicate topics.  Someone already offered to help you here