I know that! I was using both my iPad and iPhone.
I am persistent and got it figured out. The link.tidal.com is a bad link.
(At least when accessed outside of the Tidal app itself)
After logging into my Tidal account, I went to the help menu. From there I went to the heading of link a Samsung tv. The instructions were the same except for one small detail.
Within the Help menu instructions was the ability to click on “link.tidal.com” which I proceeded to do. From this new and different screen, I logged in. Now the box appeared so I could enter the code from the tv screen.
With the code entered, Tidal is now up and running on the tv.
So only use the link from within the Tidal app itself.