Deleting your account is permanent and cannot be undone. Your profile, photos, matches, messages, location and all account data will be erased immediately.
If you have an active subscription on Google Play or the App Store, cancel it there before deleting, otherwise you may continue to be charged. The subscription is managed by the store, not by the app.
Use a one-time code sent to your email instead.
You can also delete your account from inside the app: Settings → Account → Delete Account.