Hello,
I have done something similar in VBA.
Betfair Exchange API uses JSON to pull data. Their documentation is very bad and it took me a while to understand it. After you find out what is going on then it's simple. :)
For example this is the implementation to bet on a event (BACK) for today's Everton v Burnley, UNDER 2.5 with a bet of 5 (default currency for the account) and odds that will be matched at 2
{"jsonrpc": "2.0","method": "SportsAPING/v1.0/placeOrders","params": {"marketId": "1.157923781","instructions": [{"selectionId": "47972","handicap": "0","side": "BACK","orderType": "LIMIT","limitOrder": {"size": "5","price": "2"}}]},"id": 1}
Before the above order there are also some other pieces of code to get the Market ID, and Selection ID
Kind regards,
Sorin