Here are the 2 error messages I get, which mostly say the same thing. It is a security measure in the browser, so there may not be much you can do depending on the hosting/embedding settings of the web version. Showing the code for people to manually copy is often the way to work around this.
index.html:196 [Violation] Permissions policy violation: The Clipboard API has been blocked because of a permissions policy applied to the current document. See https://crbug.com/414348233 for more details.
index.html:196 Uncaught (in promise) NotAllowedError: Failed to execute 'writeText' on 'Clipboard': The Clipboard API has been blocked because of a permissions policy applied to the current document. See https://crbug.com/414348233 for more details.