Code after initializing ethers interface isn't executing

[Dnguye92]

Ethers Version

6.11.1

Search Terms

No response

Describe the Problem

I'm using this doc (https://docs.alchemy.com/docs/how-to-get-erc-20-token-balance-at-a-given-block#step-5-get-usdt-balance-at-a-particular-block) to pull block specific balances with Alchemy and Ethers v6.x. The doc is referencing what looks to be Ethers v5.x but I was able to find the v6.x equivalent. The problem I'm facing is that none of the code after creating an ethers interface is being executed. I've confirmed that all of my Alchemy related code is working as expected and that the issue lies with ethers or my use of ethers. I'm also not seeing any errors reported in the console.

Code Snippet

const getBalance = async (walletAddress) => {
  ...
  console.log("CREATING INTERFACE");
  // Create function call data -- eth_call
  let iface = new ethers.Interface([
    "function balanceOf(address) view returns (uint)"
  ]);
  // code below this comment never gets executed
  console.log("IFACE", iface);

  let data = iface.encodeFunctionData("balanceOf", [walletAddress]);
  console.log("DATA", data);

  // Get balance at a particular block -- usage of eth_call
  let balancedData = await alchemy.core.call({
    to: USDC_CONTRACT_ADDRESS,
    data: data,
  }, blockTag);

  console.log("BALANCE", balancedData)
  balancedData = (parseInt(balancedData) / 10 ** FIXED_DECIMAL_PLACE).toFixed(2);
  console.log("Balance:", balancedData, "USDT");
}

Contract ABI

["function balanceOf(address) view returns (uint)"]

Errors

N/A

Environment

Ethereum (mainnet/ropsten/rinkeby/goerli), node.js (v12 or newer)

Environment (Other)

No response