Code to Change “Leave a Comment” Text in WordPress

/* Custom 'Leave a Comment' Text */
add_filter('comment_form_defaults', 'wpflt_custom_comment_title', 20);
function wpflt_custom_comment_title( $defaults ){
  $defaults['title_reply'] = __('Type your Precious Comment', 'custom-comment-text');
  return $defaults;
}

Replace the default ‘Leave a Comment’ text in WordPress comment form to any Custom Text. Add the code to the child theme’s ‘functions.php‘ file.