The copy and paste functionality only works when using Chrome as your browser.
You will need to allow the "clipboard" permissions in Chrome as shown:
Click on the lock icon next to the url
Go to site settings it will open another browser window
Set the clipboard to allow
When you go back to the tab with our site in it there will be a message at the top of the browser that says “To apply your updated settings for this site, reload this page” and a button to reload.