It copies the content of the field and then shows an alert that confirms what was copied.
I've tested it with Chrome and Firefox which works, Edge did not.
I used a Vibrant button, which allows me to put it into a Rich Text field with other buttons, instead of a Formula URL field. It will work with the URL field as well if you remove the button code.
Hope this helps.
Dana
var text CB= URLEncode([Some Field]);
var text Alert= URLEncode([Some Field] & " Was Copied to the Clipboard");
"<a class='Vibrant Success' style=\"border:0px solid green; background-color:green; text-align: center;\"href=" &
"javascript:{" & "navigator.clipboard.writeText('" & $CB & "').then(function(){" & "},function(){" & "});" & "alert('" & $Alert & "');" & "};" & ">Copy to the Clipboard</a>"