Before creating listings, the signer must approve the item's transfer by the X2Y2: ERC 721 Delegate contract with the setApprovalForAll function on the item's contract.

To create a fixed-price listing, also referred to as an order, call the list method:

await list({
  signer: seller, // Signer of the seller
  tokenAddress, // string, contract address of NFT collection
  tokenId, // string, token ID of the NFT
  tokenStandard, // 'erc721' | 'erc1155'
  price, // string, sale price in wei eg. '1000000000000000000' for 1 ETH
  expirationTime, // number, the unix timestamp when the listing will expire, in seconds. Must be at least 15 minutes later in the future.