[iA1]

If you want to add custom meta tags such as viewport, theme-color etc, then create a new plugin at hook location parse_templates and add the following code:

    $template_hook['headinclude_javascript'] .= '
<meta name="viewport" content="width=device-width, initial-scale=1">
';

Add each meta tag in a new line after the one shown above, just before the closing ';