if you want to display the One website url in other site’s posts at bottom. you can use below code. it will display all other site links excepts current site of multisite at end of post content of “post” post type. you can change post type as your need.
add_filter('the_content','add_site_url_in_bottom',10,1);
function add_site_url_in_bottom($content)
{
global $post;
if ($post->post_type == 'post') {
if ( function_exists( 'get_sites' ) && class_exists( 'WP_Site_Query' ) ) {
$args = array(
"site__not_in" => get_current_blog_id(),
);
$sites = get_sites($args);
$content .= '<h3>Other Site URLS</h3>';
foreach ( $sites as $site ) {
switch_to_blog( $site->blog_id );
$content .= 'site url : <a href="'.get_site_url($site->blog_id).'">';
$content .= get_bloginfo( 'name' );
$content .= '</a><br>';
restore_current_blog();
}
}
}
return $content;
}
see https://prnt.sc/p9pr4z for reference.