Apple does not want us to link from outside to a note although it makes sense to have a central notes management .
There is no documented, public URL scheme for Apple Notes. Apple has never listed one in developer documentation, and there is no deep link from iCloud.com or from non-Apple platforms.
But an undocumented mechanism exists and is reachable from outside the app. Just create a Shortcut Continue reading Link to a note from desktop
I have been looking for a wikipedia-style link out symbol (wikipedia uses a svg symbol). Some websites recommend font awesome symbol /f08e others are in favor of the north east arrow #x2197; while I modfied now a code pen by thiago for the css of this wordpress child theme
a:not([href*='wjst.de'])::after {
content: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAQElEQVR42qXKwQkAIAxDUUdxtO6/RBQkQZvSi8I/pL4BoGw/XPkh4XigPmsUgh0626AjRsgxHTkUThsG2T/sIlzdTsp52kSS1wAAAABJRU5ErkJggg==);
margin: 0 3px 0 5px;
}