Add REST API to Opencart

Hi,

I'd like to manage my products with a REST API : https://codeswholesale.com/
This API can manage products, orders, etc. As explained here: https://docs.codeswholesale.com/api-documentation/

But I have no idea how to integrate it. Can I override existing products files for example?
I don't know where to start for showing products related to a REST API. Do you have a tutorial or advices?

Thanks.