Last Update on Single Post

Good day,

How to display this on modified date?
Example: Last updated on March 5, 2017 by Editorial Staff

In the loop-single-5.php, I replace <?php echo $td_mod_single->get_date(false);?> to
<?php echo the_modified_date(‘F j, Y’, ‘<div class=”the-modified-date”>Last Updated on ‘,’ by </div>’);?>

the outcome is:
By Editorial Staff -Last Updated on March 5, 2017 by

I can’t place the author on the last line and remove the dash –

Can you help me with the code to make it like this one:
Last updated on March 5, 2017 by Editorial Staff

Thank you.