WordPress Limit User File Upload Size Filter

function limit_user_file_upload_size( $size ) {
    // Set the upload size limit to 10 MB for users lacking the 'manage_options' capability.
    if ( ! current_user_can( 'manage_options' ) ) {
        // 10 MB.
        $size = 1024 * 10000;
    }
    return $size;
}
add_filter( 'upload_size_limit', 'limit_user_file_upload_size', 20 );