Duplex printing only, even if One side only used (Mac OS)

Printing with MS Word: single side only.
In Dorico, with

and 1-2 as page range, it prints duplex. What could be wrong?

The printer web page says

= Double side: OFF

This is often discussed here on the forum. Please check any of the earlier threads, e.g. this one:

I get

“Safari cannot open page … since Safari cannot connect to server localhost”.
Am I doing something wrong?

Chrome returns
ERR_CONNECTION_REFUSED

The video is from 2019, perhaps something has changed?

The video is still available:

Yes, I watched it, but localhost:631 does not work

We are talking about different things.
in the VIDEO he says: Type localhost:631 in the browsers.
I try both Chrome and Safari - both fail accessing localhost, as shown above with errors messages.

I solved it, although the instructions in the video are wrong, at least today, 2023.

Sorry – I see, it’s a security issue. I found a tip about enabling the CUPS web interface on Mac here.

The strange thing was I had to “turn it around”. I had to type the Terminal command before entering the address. It might have changed for the various Mac OS. I’m glad it was solvable.