I don't know where the problem is and cannot find it in my search, I'm having this firebase initialization:

import firebase from "firebase/compat/app";
import "firebase/compat/firestore";
import "firebase/compat/auth";

const firebaseConfig = {
  apiKey: "xxxxxxxxxx",
  authDomain: "xxxxxxxxxx",
  projectId: "xxxxxxxxxx",
  messagingSenderId: "xxxxxxxxxx",
  appId: "xxxxxxxxxx",
  measurementId: "xxxxxxxxxx",
  storageBucket: "xxxxxxxxxx",
};
  
firebase.initializeApp(firebaseConfig);
firebase.db = firebase.firestore();
firebase.auth = firebase.auth();

export default firebase;

And want to check if in a login form the user is in my users db with:

import firebase from "../Config/firebase";

  const onSubmit = async (data) => {

    try {
      const responseUser = await firebase.auth.singInWithEmailAndPassword(
        data.mail,
        data.password
      );
      console.log(responseUser.user.uid);

      }
    } catch (e) {
      console.log("ERROR ", e);
    }
  };

From that I get this error:

ERROR  TypeError: _Config_firebase__WEBPACK_IMPORTED_MODULE_3__.default.auth.singInWithEmailAndPassword is not a function
    onSubmit (index):24
    handleSubmit (index):992
    React 14
    unstable_runWithPriority (index):468
    React 15
    js (index):7
    js main.chunk.js:5996
    Webpack 7

I can read and write with this firebase set-up already, but cannot check get a reply from the user auth. If anyone has some ideas I would really appreciate it! thanks in advance