By default, admin 2020 disables the normal WordPress screen options but it does allow you to bring them back if you wish.
Click on the the top right user icon in your WordPress dashboard to access the user flyout menu.
Select the preferences tab from the user menu.
Once there you will see an option called ‘enable screen options’, enable this and refresh the page.
After following the above steps you should now see a settings icon in the right side of the admin bar, clicking this will toggle screen options.