Unable to get User Information

# Unable to get user information

## Code used to reproduce
```js
import { LeetCode } from "leetcode-query";

const leetcode = new LeetCode();
const user = await leetcode.user("username");
```

## Error

```bash
Uncaught (in promise) TypeError: Failed to execute 'fetch' on 'Window': Illegal invocation
at _fetch (index.js:71:1)
at get_csrf (index.js:87:1)
at Credential.init (index.js:111:1)
at getUser (Card.js:10:1)
at Card (Card.js:15:1)
at renderWithHooks (react-dom.development.js:15486:1)
at mountIndeterminateComponent (react-dom.development.js:20103:1)
at beginWork (react-dom.development.js:21626:1)
at beginWork$1 (react-dom.development.js:27465:1)
at performUnitOfWork (react-dom.development.js:26596:1)
```

Help me with this. @JacobLinCool

The failure is reported through index.js at _fetch, get_csrf, and Credential.init, with Card.js calling getUser. Reproduce the browser call shown in the issue and trace the fetch invocation; done means leetcode.user("username") returns user information without the Illegal invocation error.

Written by the indexing model from the issue text.