react-native-obfuscating-transformer is not obfuscating any code

I am looking to enable react-native-obfuscating-transformer but can't seem to get my code obfuscated.

I have the following in my metro.config.js

  transformer: {
    getTransformOptions: async () => ({
      transform: {
        experimentalImportSupport: false,
        inlineRequires: false,
      },
    }),
    babelTransformerPath: require.resolve('./transformer'), // add here the transformer.js
  },

I have the following in my transformer.js file:

const obfuscatingTransformer = require('react-native-obfuscating-transformer');
const typescriptTransformer = require('react-native-typescript-transformer');

const filter = (filename) => {
  return filename.startsWith('src/path-to-file/index.tsx');
};

module.exports = obfuscatingTransformer({
  // this configuration is based on https://github.com/javascript-obfuscator/javascript-obfuscator
  obfuscatorOptions: {
    compact: true,
    controlFlowFlattening: false,
    deadCodeInjection: false,
    debugProtection: false,
    debugProtectionInterval: false,
    disableConsoleOutput: true,
    identifierNamesGenerator: 'hexadecimal',
    log: false,
    renameGlobals: false,
    rotateStringArray: true,
    selfDefending: true,
    shuffleStringArray: true,
    splitStrings: false,
    stringArray: true,
    stringArrayEncoding: false,
    stringArrayThreshold: 0.75,
    unicodeEscapeSequence: false,
  },
  upstreamTransformer: typescriptTransformer,
  emitObfuscatedFiles: true,
  enableInDevelopment: true,
  filter: filter,
  trace: true,
});

However when I build my app (I am testing via yarn start) I can see that my files are "obfuscated"

transform[stdout]: Obfuscating src/path-to-file/index.tsx

However comparing the normal file vs it's .obfuscated. counterpart shows nothing has been obfuscated.

Normal file:

const myApiKey = 'foo';

Obfuscated file:

var myApiKey = 'foo';

Any help would be largely appreciated.

Edit: I have opted for obfuscator-io-metro-plugin which has successfully obfuscated my code.