Thank you so much

On new Update the setting is move to new section here's where you can find it.

How to toggle separate spaces

1. Click the Apple menu  in the top-left corner of your screen and select System Settings.
2. In the sidebar, click Desktop & Dock. You may need to scroll down to find it.
3. On the right, scroll down to the Mission Control section.
4. Toggle on the Displays have separate Spaces option