Facebook API Integration Assistance

We are currently running Facebook campaigns for 1) Lead Ads and 2) Website Conversions. We want to A) Post our offline sales data back into Facebook's API for offline optimization of both campaign types and B) retrieve ad spend data through Facebook's API. The sales data is stored in proprietary software we built in house. This project is to:
1) Confirm ads are set up correctly to pass offline sales and adjust if necessary (Making sure tracking_spec is correct
2) Perform or assist in house developer with Facebook integration into API to post offline sales data
3) Perform or assist in house developer with Facebook integration into API to retrieve ad spend data