Odd. That is not there for me and I cannot add it :( I have the same problem as OP. I wish it were simple.

The “News” icon (to open a paywalled article in Apple News) only appears in the Share sheet in Safari.app proper.

It’s a bit amusing to me that this sounds like another, different anti-trust issue. Apple’s browser having this feature, which other browser vendors (presumably) can’t add, to open another app would also look bad to an EU judge.