Email Verification without creating new user - Firebase

Question

In firebase you can create an email verfication easily. However you need to create a new user. I would like to send an email verfication to a user's email without creating a new user.

This is an unsubscribe function where I want the user to be able to unsubscribe by entering an email. I then check if the user can log into that email via verification.

I cannot simply check if the email is authenticated as this allows users to delete any user.

Unsubscribe code

import { auth, db } from '../../../firebase-config'
export default function SubscribePopup(props) {
    if (props.subscribe){
        ...
    }
    else{
        #email verification ..
        # if passes delete user
        const userAuth = auth.currentUser;

        userAuth.delete().then(() => {
            console.log("Deleted user", email);
        }).catch((error) => {
            console.log("Error deleting user:", error);
        });

        setUnsubscribePop(false);
        localStorage.setItem('signedIn', false);
    }
}