How to display a variable in the right place?

Question

WordPress

The following code displays the date the post was modified, a date icon ( ) and more.<span class="posted-on">

function awaken_posted_on() {
  $abc = the_modified_date();	
  //$time_string = awaken_posted_datetime();

  $posted_on = $time_string ;
  

  $byline = '<span class="author vcard">' . esc_html( get_the_author() ) .'</span>';

  echo '<span class="posted-on">' . '</span><span class="byline">' . $byline . '</span>';

}

Question: how to display a variable after the date icon ?
This construct doesn't work:

echo '<span class="posted-on">'. $abc . '</span><span class="byline">' . $byline . '</span>';

Answer 1

replace:
the_modified_date()
with:
get_the_modified_date();