const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({deadline: 1, maker: '<string>', orderHash: '<string>', signature: '<string>'})
};

fetch('https://swap.ggp.gg/api/{blockchain}/orders/cancel', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "success": true
}