I wrote a filter hook for wp_handle_upload_prefilter to crop and add watermark simultaneously when upload new image to wordpress media. It works in every page that there is wp media upload, but I want to execute this filter hook just in a certain page. (i.e. in Dokan dashboard)

/dashboard/upload_image URL link.

Thank you for helping me...

codes to create new item and page in Dokan dahsboard:

add_filter( 'dokan_query_var_filter', 
'dokan_load_document_menu_add_product' );
function dokan_load_document_menu_add_product($query_vars){
  $query_vars['upload_image'] = 'upload_image';
  return $query_vars;
}

add_filter( 'dokan_get_dashboard_nav', 'dokan_add_new_product_menu' );
function dokan_add_new_product_menu( $urls ) {
$urls['upload_image'] = array(
    'title' => __( 'Upload Image', 'dokan'),
    'icon'  => '<i class="fa fa-user"></i>',
    'url'   => dokan_get_navigation_url( 'upload_image' ),
    'pos'   => 42
);
 return $urls;
}

add_action( 'dokan_load_custom_template', 'dokan_load_template' );
function dokan_load_template( $query_vars ) {
   if ( isset( $query_vars['upload_image'] ) ) {
       include YDE_INC.'upload_image.php';
   }
}

YDE_INC is plugin_dir_path to folder in which upload_image.php exists.

Filter to modify uploading image:

add_filter('wp_handle_upload_prefilter', 'custom_upload_filter' );
function custom_upload_filter( $file ){ 
    ...Codes to crop and watermark the new image for uploading... 
}