flutter: [ERROR]: CreateAuthChallenge failed with error SyntaxError: await is only valid in async function

Getting the captioned error message onTap signUpButton() within AuthenticatorForm(). Seems like a very straightforward error message, but can't seem to identify what's wrong.

Here is my createAuthChallenge.js

const digitGenerator = require('crypto-secure-random-digit');

function sendSMS(phone, code) {
  const params = {
    Message: code,
    PhoneNumber: phone,
  };
  return new AWS.SNS({apiVersion: '2010-03-31'}).publish(params).promise();
}

async function createAuthChallenge(event) {
  if (event.request.challengeName === 'CUSTOM_CHALLENGE') {
    const randomDigits = digitGenerator.randomDigits(6).join('');
    const challengeCode = String(randomDigits).join('');
    await sendSMS(event.request.userAttributes.phone_number, challengeCode);
  
    event.response.privateChallengeParameters = {};
    event.response.privateChallengeParameters.answer = challengeCode;
  }
}

exports.handler = async (event) => {
  createAuthChallenge(event);
};

And my package.json for the same

{
  "name": "XYZ",
  "version": "2.0.0",
  "description": "Lambda function generated by Amplify",
  "main": "index.js",
  "license": "Apache-2.0",
  "devDependencies": {
    "@types/aws-lambda": "^8.10.92"
  },
  "dependencies": {
    "crypto-secure-random-digit": "^1.0.9"
  }
}

I can't seem to find the right solution for this, can anyone help please?