Ok, I needed to update my iOS from 16 to 17 for this new feature of widget sharing to work, but have now my familiar widgets back. Thanks for the tipp.
I stopped watching each Keynote a while ago where they show every need little new feature and so did not know.
Only little downer is now when I click in the widget to see more details it opens the website in Safri and not the Windy WebApp I created from Safari and so it behaves a bit different to the native app. Well I guess you can not have everything. :S

Ok, thats sad news for me, since I most liked and used the widgets of the Windy App and that are not covered by a Safari web-app.
Since it looks like Apple has no good own website widget apart from opening the reading list in Safari I will have to see if I find a 3rd party web widget to create a workaround at least for the radar view. But I don't see I can cover the nice 5 day weather forecast widget with it. Thanks for your answer.

My old app 38.01049 still works fine on MacOS Sonoma but I get warnings that I should update the app since the support of the old app will be soon disabled. But when I look in AppStore I see that newest app 41.020355 is not compatible with my device and only iPhone, iPads and Apple Watch/Vision are supported.

Did you gave up on supporting a Mac version or will there be an Update that works with Macs again?