The Darts API is one REST API over the whole darts archive. Every call is a GET (one is a POST) to https://api.dartsapi.com/v1, answers in JSON, and needs your key.
1. Get a key
Sign in with Google and a free key is issued at once, with no card. It lives on your dashboard. Keep it in an environment variable rather than in your code.
2. Check it works
/v1/usage answers with your plan, your window and today's counters. It is the call to make first, and the one lab tools make before doing any work.
curl https://api.dartsapi.com/v1/usage \ -H "Authorization: Bearer $DARTS_API_KEY"
3. Make a real call
Every player, match and competition has an id that carries its type: pl_ for a player, mt_ for a match, cp_ for a competition, ev_ for an edition. Find a player by name, then use their id everywhere else.
curl "https://api.dartsapi.com/v1/players?q=littler" \ -H "Authorization: Bearer $DARTS_API_KEY" curl "https://api.dartsapi.com/v1/results?player_id=pl_VEB8HM&limit=5" \ -H "Authorization: Bearer $DARTS_API_KEY"
Every response has the same shape
What you asked for is in data. Everything about the answer is in meta: your plan, the window it was answered within, a next_cursor when there is more, a request_id to quote if you ever need help, and data_as_of, how fresh the archive was when it answered.