You can set the footer copyright text of your site. The copyright notice also tells site visitors who own the website, though it sometimes also includes information about the company that developed the site or the template the site owner used.

In your WP Admin Panel, go to Appearance => Customizing ▸ Footer copyright settings ▸ Copyright text

Here you can find Copyright text input field, Enter your text here then Save & Publish. Refer to attach the screenshot.