iOS 18 Sign Out is Not Available Due to Restrictions
If you're unable to sign out of Telegram on your iPhone due to restrictions, here’s a detailed approach to address this issue:
To fix this issue you need to turn off Screen Time Restrictions.
1. Go to Settings on your iPhone.
2. On the Settings, find and tap Screen Time:
3. On the Screen Time. scroll down and tap "Change Screen Time Passcode".
4. Select Turn Off Screen Time Passcode.