const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    maker: '<string>',
    makerSrcOrToken: '<string>',
    params: {
      makerTraits: {
        allowMultipleFills: true,
        allowPartialFills: true,
        allowedSenderSuffix: '<string>',
        expiration: 1,
        hasExtension: true,
        needCheckEpochManager: true,
        needPostInteractionCall: true,
        needPreInteractionCall: true,
        nonceOrEpoch: 1,
        series: 1,
        unwrapWeth: true,
        usePermit2: true
      },
      makingAmount: '<string>',
      salt: '<string>',
      signature: '<string>',
      takingAmount: '<string>',
      extension: '<string>'
    },
    takerSrcOrToken: '<string>'
  })
};

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

{
  "orderHash": "0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
}