If you want to switch windows such as Powerpoint to browser while screen sharing, please share the desktop while screen sharing.
When sharing windows
Screen sharing displays only that window.
When sharing the desktop
Screen sharing selects the desktop.
You can switch between windows and applications.
How to share PowerPoint screen?
To make it full screen when sharing the screen
When sharing the screen in full screen
How can I share high-quality videos and other materials?
Enable recording disclaimer (recording consent / recording consent)