App not opening
What to do when an app does not open?
iPhone 8 Plus, iOS 15
First, try a forced restart.
• Press and quickly release the volume up button
• Press and quickly release the volume down button
• Press and hold the side button.
• When the Apple logo appears, release the button.
https://support.apple.com/en-in/guide/iphone/iph8903c3ee6/ios
If that doesn't work, contact the app developer about the issue.
How to contact an app developer.
https://support.apple.com/en-us/HT207959