How to use ThisIsMe api

Am trying to use an api called thisisme and here the url: https://uat-api.thisisme.com/v2/

I deployed my website with Forge and to access the api, it states that I need to generate an ssl certificate pair and a Certificate Signing Request.

It happens that I already have an SSL certificate generated by Forge. Is it normal to have multiple SSL keys and CSR?

Where in the server do I generate the new SSL and CSR? In the root directory or must I run the command "cd mysite.co.za" and do everything under my current site?

Another question is that, since I am only allowed to make use of the API in live server, how is this going to work with my github commits?

Hope I could explain correctly