premitSnippet.ts

async function getPermitSignature(signer: any, token: any, spender: any, value: any, deadline: any) {
    const [nonce, name, version, chainId] = await Promise.all([
      token.nonces(signer.address),
      token.name(),
      "1",
      80001,
    ])

    console.log(nonce, name, version, chainId)
  
    return ethers.utils.splitSignature(
      await signer._signTypedData(
        {
          name,
          version,
          chainId,
          verifyingContract: token.address,
        },
        {
          Permit: [
            {
              name: "owner",
              type: "address",
            },
            {
              name: "spender",
              type: "address",
            },
            {
              name: "value",
              type: "uint256",
            },
            {
              name: "nonce",
              type: "uint256",
            },
            {
              name: "deadline",
              type: "uint256",
            },
          ],
        },
        {
          owner: signer.address,
          spender,
          value,
          nonce,
          deadline,
        }
      )
    )
  }

use.ts

    const deadline = Math.floor(Date.now() + 600);

    const { v, r, s } = await getPermitSignature(
        contractOwner,
        Token,
        DIAMOND_ADDRESS,
        NUM_IN,
        deadline
    )