Add more schedule options for Course expiry email. Like notify student 30 days in advance.

functions.php

add_filter('wplms_email_schedule',function($settings){

  foreach($settings as  $i=>$setting){
    if($setting['name']==='expire_schedule'){
      $hours = 30*24;
      $settings[$i]['options'][$hours]='Before 30 days of course expiry';
      $settings[$i]['options'][$hours*2]='Before 60 days of course expiry';
      $settings[$i]['options'][$hours*3]='Before 90 days of course expiry';
    }
  }
  return $settings;
});