Open App Store and install Cawice app

Cawice on App Store

Login to Google Account as Camera

Select iphone usage

Open Settings app and select Screen Time

Settings->Screen Time

Config Screen Time first time usage

Screen Time first time access 1

Select "This is My iPhone" to continue

Screen Time first time access 2

Select "Always Allowed" to see app list

Go to allowed app list screen

Find Cawice and tap on the row to add it to Allowed Apps

Add Cawice app to Allowed app list

Only keep Cawice in Allowed Apps list

Remove others apps from the list

Make sure you see this on your device

Final screen of Alway Allowed

Select "Downtime" from Screen Time screen

Open downtime screen

Turn on Scheduled downtime

Downtime screen

Select "Every day" option

Select Every day schedule

Set From: 10:00 PM and To: 9:59 PM

Set time of schedule

Come back to bottom of Screen Time and find "Use Screen Time Passcode"

Set time of schedule

Set the passcode you want to confirm it.

Set screen time passcode