Missing translation function

A string cannot be translated because of a missing translation function. The string is located in wp-last-modified-info/inc/Api/Callbacks/ManagerCallbacks.php row 246:

$default = '<p class="post-modified-info">Last Updated on %post_modified% by <a href="%author_url%" target="_blank" class="last-modified-author">%author_name%</a></p>';

My fix:

$default = '<p class="post-modified-info">' . __( 'Last Updated on', 'wp-last-modified-info') . ' %post_modified% ' . __('by', 'wp-last-modified-info') .  ' <a href="%author_url%" target="_blank" class="last-modified-author">%author_name%</a></p>';