FaceTime, Camera and Safari disappeared after latest update to iPadOS 13.6

Begin with a forced-restart - as this will often resolve an isolated or unexpected issue:

• On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On an iPad with Face ID: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.

If the forced restart doesn’t resolve the issue, ensure that you have either an iCloud or iTunes backup of your iPad - then fully reset the iPad. After your iPad finishes the reset, you have the option to restore your locally stored data from your backup.

How to back up your iPhone, iPad and iPod touch – Apple Support

To reset your iPad:

Settings > General > Reset > Erase All Content & Settings

You are very welcome. I’m delighted that the problem has been fully resolved.