You may use Apple Configurator for Mac app to restart your iPhone - just connect your iPhone to Mac (if you have one of course), right click your iPhone in Apple Configurator for Mac app and choose Advanced - Restart Device.
[link|https://support.apple.com/en-gb/guide/apple-configurator-mac/apd647013cbb/mac|Official Apple Support guide for this is available here|new_window=true]
You’ll find Apple Configurator for Mac app on the [link|https://apps.apple.com/ua/app/apple-configurator/id1037126344?mt=12|Mac App Store as a free download|new_window=true]