TypeError: fs.readFileSync is not a function Off Basic Install

I'm stumped - pretty simple app (I'm new to Node):

App.js

import * as RNFS from 'react-native-fs';
var config_full;
// readFile(filepath: string, encoding?: string)
RNFS.readFile('./config.toml', 'utf-8').then(res => {
    config_full = toml.parse(res);
})
.catch(err => {
    console.log(err.message, err.code);
});

Package.json

{
  "name": "samples-dashboard",
  "version": "0.1.0",
  "private": false,
  "type": "module",
  "dependencies": {
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.5.0",
    "@testing-library/user-event": "^7.2.1",
    "fs": "0.0.1-security",
    "gremlin": "^3.4.6",
    "match-sorter": "^4.1.0",
    "namor": "^2.0.2",
    "react": "^16.13.1",
    "react-dom": "^16.13.1",
    "react-native-fs": "^2.16.6",
    "react-scripts": "3.4.1",
    "react-table": "^7.1.0",
    "styled-components": "^5.1.1",
    "toml": "^3.0.0"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject",
    "predeploy": "npm run build",
    "deploy": "gh-pages -d build"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  },
  "devDependencies": {
    "gh-pages": "^2.2.0"
  }
}

And I get an error:

Failed to compile
./node_modules/react-native-fs/FS.common.js
SyntaxError: /node_modules/react-native-fs/FS.common.js: Unexpected token, expected ";" (32:5)

  30 | var normalizeFilePath = (path) => (path.startsWith('file://') ? path.slice(7) : path);
  31 | 
> 32 | type MkdirOptions = {
     |      ^
  33 |   NSURLIsExcludedFromBackupKey?: boolean; // iOS only
  34 |   NSFileProtectionKey?: string; // IOS only
  35 | };

I totally don't care what I use to load from the .toml file - just need to load a few things off disk. What should I be using?

To be clear, I don't need to deliver this file to the browser, I want the server to load the file and provide the value of the .toml to the variable.

I've checked the following and none seem to work:

• TypeError: fs.readFileSync is not a function
• https://dev-yakuza.github.io/en/react-native/react-native-fs/#read-file
• Uncaught TypeError: fs.readFileSync is not a function
• Error: fs.readFileSync is not a function
• fs.readFileSync is not a function Meteor, React

My best hope was the core docs - https://github.com/alexbeletsky/toml-js - but none of the file system packages seemed to work there either.