How can I have the battery percentage instead of battery icon on home screen?

That option doesn’t work anymore either. Now you can’t show percent numbers in widgets or on any other form or shape on iPhone 13 on iOS 15.1

Tim, your “users” wants battery percentage in icons to show in the status itself. Stop playing the battery games!!! Bring it back!!!! Listen to your users!!!

There is no option to display it permanently at the top of the screen. The only options are to open Control Center by swiping down from the top right corner or to display it in a widget. If you want to add or remove the Battery widget from the screen, see: Use widgets on your iPhone and iPod touch - Apple Support