Hi! I understand you're having trouble adding a payee using the PNC mobile app on your iPhone. To help you better, could you tell me if you see any specific error messages when you try to add a payee? Also, have you been able to add payees before, or is this your first time? This info will help me guide you more precisely.

Meanwhile, here are some general steps you can try on your iPhone with iOS 18.7:

1. Check App Version: Make sure your PNC app is updated to the latest version available in the App Store. Sometimes app bugs that affect features like adding payees are fixed in updates.

2. Confirm Network Connection: Ensure your iPhone has a stable internet connection, either Wi-Fi or cellular. Unstable or restricted networks can cause issues when adding payees.

3. Restart the App: Close the app completely (swipe up from the bottom and swipe the app off screen) and then reopen it.

4. Log Out and Log In: Sometimes, logging out of your PNC app and then logging back in can refresh your account data and remove glitches.

5. Verify Your Account Permissions: Adding payees might require certain account permissions or security settings like multi-factor authentication. Check if you need to complete any verification steps.

6. Try Adding Payee via Online Banking Website: If the mobile app continues to have issues, try logging into your PNC online banking via Safari on your iPhone and see if you can add the payee there. If it works online but not in the app, that points to a mobile app issue.

If after trying these steps it still doesn't work, please let me know any specific error or behavior you experience, and we can explore more advanced troubleshooting. Also, if you suspect any app or service outages, I can help verify that for you.

Are you able to share more details on what happens when you try to add a payee? That will help me tailor the next steps for you.