How to add HTTPS to this Laravel variable?

I'm trying to add HTTPS to my Laravel variable but to no avail, need help, any help will be highly appreciative!

$verifyurl = $eventName->event_url
    . '/verify-email/' . $event->verifyString 
    . '/' . $user['event_url_id'];
$content = "<b>verify email here  :</b>"
    . "<a href=" . $verifyurl . " target='_blank'>"
    . $eventName->event_url . "</a>"; 

via Chebli Mohamed