⛔ Combine text and php code together NOOB question sorry

[MyPhp]

Hi all sorry for the total noob question. How do I add this:
. $this->db->escape($referrer) .
to this:
$msg = "Referer found. Referer: ";

I tried:
$msg = "Referer found. Referer: += . $this->db->escape($referrer) . "

[Valkrider]

You need to close out the text before adding the php

$msg = "Referer found. Referer: ". $this->db->escape($referrer);