How to get the Apple Weather App if it's not already installed

Since DarkSky is going away I'm looking into the Free Apple Weather App which is Assimilating Dark Sky. I have the weather app on my new phone, but I cannot find it in the app store to install on my iPad. Perhaps this is because the iPad is an older one. It's running 15.5 but apparently never got the Weather App as part of the installed Apple Apps.

I've scrolled through all the weather apps on the App Store, accessing from the iPad, but no luck: it's simply not there. On my Mac computer browser, there's a claim that it exists (See attached.)

Maybe I'll try plugging the iPad into the Mac and see if I can find & download the app via iTunes or something ... (is this a silly idea or something that I've actually done before in the past and vaguely remember.)