All /api endpoint are POST requests with content-type=application/json. They accept and return JSON bodies.
request: http POST "https://scrabble-interview-3phapd5lx-opendoor.vercel.app/api/scrabble/level" {"level": YOUR-LEVEL}response: {board: matrix[i][j] = letter|null, candidate: array[{row: i, col: j, letter:a-z}]}