如何检查WordPress多站点的超级管理员？

I want to check super admin in wp_config.php and I've tried the following code without any result.

if (get_super_admins()) {
    echo 'You are super admin';
}

Kindly help me thanks.

Try this:

if ( is_super_admin() ) {
    echo 'You are super admin';
}

It will not work in wp-config.php as a user has not been loaded at this stage. There is essentially no user to check for.

Use it in your theme functions.php file or custom plugin code.