I can search for and find Samsung Notes in the Windows 11 store, but there is not install button.
The only way I could install it was to go to the web version of the store and
Click on the ellipsis [...] and choose "install on my devices".
I had the same issue - and by luck found the solution.
There are 2 versions of Samsung Notes in the Store.
Samsung Notes => you cannot install
S Notes => that's the one - and it syncs with your mobile S Notes.
S Notes and Samsung Notes are 2 different Apps/Platforms.
S Notes only hosts notes made in the older outdated S Notes App that works primarily with the S Pen.
Samsung Notes is the native note-taking app that is used to take notes on newer products.
If Samsung Notes really is not compatible with Windows 11, which I'm facing this issue right now, all of my notes from my tablet cannot be viewed on my PC. Is there any word on when this will be updated for Windows 11? Shocked it's not compatible since Windows 10 and 11 are basically the same architecture.