Can't get started with recording !

Sorry, new to Audacity so almost certainly a dumb question but here goes !

I’m trying to record from an old audio cassette to my PC as an audio file. I’m running Windows 10 and I have connected my Technics Cassette Deck from its two stereo line-out plugs to the line-in socket on my sound card via a small stereo jack.

I hit play on the deck and I see the bouncing sound bars suggesting all is good but I hear nothing … complete silence.

Any attempt to find the “recording device” on Audacity or on the PC states there is no device / input device.

What am I doing wrong here ?

See this tutorial in the manual:

In particular this page: