I've these details, exposed to many websites developed for me by me.
I use these to try sending notifications to my users/subscribers. But I was thinking if someone evil gets these key, what can they do.
const firebaseConfig = {
apiKey: '----xxxx--------',
authDomain: '----xx-----',
projectId: '---x-----',
storageBucket: '----x----',
messagingSenderId: '----x----',
appId: '---x----',
measurementId: '---x----',
};
initializeApp(firebaseConfig);
const vapidkey = '--xxxx--';