"Probably"

... but it depends on the context.

• Where does the webpage come from?
• What is rendering the webpage?
• Where does Perl fit into the system?

You could be talking about having a proxy server, written in Perl, that modifies a page before it gets to the browser.

You could be talking about a bot written in Perl that interacts with a website without a browser being involved.

You could be talking Perl embedded in the server side application.

How you would go about this would depend on what you are actually trying to achieve.