title: TS2304:Cannot find name 'btoa'
body: <p>I'm using <code>btoa</code> method for hashing username, password which seems to work fine but this error shows up in my TypeScript errors - WebStorm. How to resolve this?</p>
  
  <p><strong>js code</strong></p>
  
  <pre><code>let base64hash = btoa(user.username+ ':' + user.key);
  </code></pre>
  
  <p><strong>tsconfig.json</strong></p>
  
  <pre><code>/* tsconfig.json */
  {
    "compileOnSave": false,
    "compilerOptions": {
      "outDir": "./dist/out-tsc",
      "sourceMap": true,
      "declaration": false,
      "moduleResolution": "node",
      "emitDecoratorMetadata": true,
      "experimentalDecorators": true,
      "lib": [
        "es2016"
      ]
    }
  }
  </code></pre>