Indeed, in the "new UI", the admin page link is not there. Or maybe, I just cannot find it. If you switch to the old UI, it's under your profile icon.
Go back to previous design:
a5abd516-ad6c-4ef2-b33b-f5acd12039a7-image.png
Admin page link is below profile icon:
27c6ff0b-e9bd-4492-9501-393d93ce00b1-image.png
Admin page:
bd5430b7-2526-473d-8cef-533e820bd76d-image.png