Hi, I want to pull actual revenue into our Salesforce org from our company's Data warehouse, but we don't have an API to call. What can be the other ways to achieve this.

Hi All, 
Is there an easy way to integrate Salesforce Lightning with Github only to track Github issues link within the associated Opportunity?
Right now I’m trying to manually start to map Opportunities to Github issues so I can measure what percentage of SalesEng work is resulting in closed opportunities; as well as make it easier for Sales to open up tickets and for information to get pre-populated so that necessary information is provided to SalesEng.
Any help will be appreciated!