How i can remove Working Functionality of my header & footer plugin from backend files but in front end plugin need to show that plugin activate

One option would be to remove the Header & Footer plugin from the site, and instead use Google Tag Manager. GTM plugins should only insert scripts on the front end and not in the admin, and GTM itself has a separate dashboard where users can add and remove scripts, so no deployment is needed, just like with the plugin you’re currently using.