LazyMint using EIP712

LazyMint.ts

// sign a message for LazyMintVoucher
  const data = {
    receiver: alice.address,
    displayTypes: [
      ethers.utils.hexDataSlice(ethers.utils.formatBytes32String("paint"), 0, 16),
      ethers.utils.hexDataSlice(ethers.utils.formatBytes32String("wheel"), 0, 16),
      ethers.utils.hexDataSlice(ethers.utils.formatBytes32String("engine"), 0, 16),
    ],
    traitTypes: [
      ethers.utils.hexDataSlice(ethers.utils.formatBytes32String("paint"), 0, 16),
      ethers.utils.hexDataSlice(ethers.utils.formatBytes32String("wheel"), 0, 16),
      ethers.utils.hexDataSlice(ethers.utils.formatBytes32String("engine"), 0, 16),
    ],
    values: [
      ethers.utils.hexDataSlice(ethers.utils.formatBytes32String("blue"), 0, 16),
      ethers.utils.hexDataSlice(ethers.utils.formatBytes32String("Alloy"), 0, 16),
      ethers.utils.hexDataSlice(ethers.utils.formatBytes32String("v8"), 0, 16),
    ],
  };
  const typedDomain = {
    name: SIGNING_DOMAIN,
    version: SIGNATURE_VERSION,
    chainId: network.config.chainId,
    verifyingContract: lazyMint.address,
  };
  const signature = await admin._signTypedData(typedDomain, SIGNATURE_TYPES, data);
  const voucher = {
    ...data,
    signature,
  };
  // mint a token to alice
  await lazyMint.lazyMint(voucher);