In class.subscribe.php
Find
$GLOBALS['SubscriptionMessage'] = GetLang('NewsletterSubscribedSuccessfully') . sprintf(" <a href='%s'>%s.</a>", $GLOBALS['ShopPath'], GetLang('Continue'));
Add after
$GLOBALS['SubscriptionCrisp'] = "<script>\$crisp.push([\"set\", \"user:email\", [\"$email\"]]);\$crisp.push([\"set\", \"user:nickname\", [\"$first_name\"]]);</script>";
In Panels/NewsletterContent.html
Find
%%GLOBAL_SubscriptionMessage%%
Add after
%%GLOBAL_SubscriptionCrisp%%