web3swift: Failed to fetch gas estimate when sending erc20

Trying to send an erc20 token but getting a Web3Error “Failed to fetch gas estimate”. Here is a snippet of my code:

   let amount = Web3.Utils.parseToBigUInt(tokenAmount, units: .eth)
        var options = TransactionOptions.defaultOptions
        options.gasPrice = gasPrice // is calculated as follows web3Main.eth.getGasPrice()
        options.gasLimit = gasLimit //set to BigUInt(50000)
        options.from = EthereumAddress(from)
        options.to = ethToAddress
        options.value = amount

      guard let myTransaction = contract.method("transfer", parameters: [ethToAddress, amount] as [AnyObject], extraData: Data(), transactionOptions: options) else {
            throw Web3Error.transactionSerializationError
        }
        
        let myRes = try myTransaction.send(password: "PASSWORD", transactionOptions: options)

Produces error on the last line. Any ideas?