401 Unauthorized error Firebase using Angular

I updated my write rules for Firebase Realtime database and I am trying to modify my POST requests to first be authenticated. No matter what I try I always get 401 (Unauthorized) error in my console.

These are my rules:

{
  "rules": {
     ".read": "true",
     ".write": "auth != null"
  }
}

This is part of my app.module.ts:

import firebase from 'firebase/compat/app';

import { environment } from '../environments/environment';
firebase.initializeApp(environment.firebase)

Environment was copied from web app that I created in Firebase.

And this is my code for posting in my component:

  writeDataToDatabase(data: any): Observable<any> {
    const email = 'mail@gmail.com';
    const password = 'pass';
  
    // Authenticate the user
    return from(firebase.auth().signInWithEmailAndPassword(email, password)).pipe(
      switchMap((userCredential: any) => {
        // User is now authenticated
        console.log('Authentication successful');
        console.log(userCredential); // Log userCredential to verify its value
    
        // Get the access token from the user credential
        return from(userCredential.user.getIdToken()).pipe(
          switchMap((accessToken) => {
            // Create headers and add the access token
            const headers = new HttpHeaders({
              'Content-Type': 'application/json',
              Authorization: `Bearer ${accessToken}`
            });
    
            console.log(headers); // Log headers to verify its value
    
            // Make the HTTP request with the headers
            return this.httpClient.get('<URL>/ip.json', { headers });
          })
        );
      })
    );
  }

And then NgOnInit:

    const data = { name: 'John Doe', age: 25 };

    this.writeDataToDatabase(data).subscribe(
      response => {
        console.log('Data written successfully:', response);
      },
      error => {
        console.error('Error writing data:', error);
      }
    );

It throws me 401 Unauthorized error. User with the credentials is added to the Authorization in Firebase Console (when I give wrong credentials it throws me an error regarding the credentials so I am 100% sure they are good)

Does anyone know what is wrong here? I would really appreciate help.

From the Firebase documentation authenticating REST API calls with an ID token:

> To send authenticated requests to the Realtime Database REST API, pass the ID token generated above as the auth=<ID_TOKEN> query string parameter. Here is an example curl request to read Ada's name:
>
> curl "https://<DATABASE_NAME>.firebaseio.com/users/ada/name.json?auth=<ID_TOKEN>"

So you'll see that you need to pass the ID token as a parameter to the request, not in an Authorization header.