Hi! I see you're having trouble logging into the Trade Republic app on your iPhone with iOS 18.6. Let's work through this together and get you back into your account.

First, just to clarify:
- Are you entering your phone number linked to your account correctly?
- Are you seeing any error messages when you try to log in? If so, what do they say?
- Have you tried restarting the app or your phone?

While waiting for your details, here are a few common steps to try:

1. Restart the app: Close the Trade Republic app completely (swipe it away from the app switcher) and reopen it.
2. Check your internet connection: Make sure you have a stable Wi-Fi or cellular data connection.
3. Re-enter login details carefully: On the login screen, enter your phone number linked to your Trade Republic account, and follow the prompts carefully.
4. Update or reinstall the app: Sometimes login issues occur due to app glitches. Go to the App Store, check if there's an update, or uninstall and reinstall the app.
5. Reset password if needed: If you suspect your password or PIN is the issue, try resetting it using the app’s password reset option.

If after these steps you still can’t log in, there might be an account lock or other technical issues.

Let me know what you’ve already tried or what errors you see, and I’ll guide you further!