Turns out was easy;
add_action('admin_menu', 'move_smush_menu_page');
function move_smush_menu_page()
{
add_submenu_page('upload.php', 'Smush', 'Smush', 'manage_options', 'smush');
remove_menu_page( 'smush' );
}`
Turns out was easy;
add_action('admin_menu', 'move_smush_menu_page');
function move_smush_menu_page()
{
add_submenu_page('upload.php', 'Smush', 'Smush', 'manage_options', 'smush');
remove_menu_page( 'smush' );
}`