

Everything after the # character in the URL is called an anchor and it’s not actually being sent to the website server so it’s meant for your browser (though the server can see it using javascript). The anchor can point to any ID in the HTML of the web page and browser will scroll it into view on page load. You can find the ID of any element using right click -> inspect though not all elements have explicit ids.
I wonder whether Meta will try to lock down cross platform access now.
Currently Beeper still works everywhere and EU’S DMA (Digital Markets Act) still has WhatsApp as gate keeper which is required to interpolate with other chat apps. However “WhatsApp stories” are entirely different from chat so that means they can block all of that and this is probably how Meta will approach future WhatsApp updates - more shit to lock people in WhatsApp that isnt directly chat related because thats the only way to show people ads.