Add php into js urlencoded.append [duplicate]

I’m pulling customer session data like so:

get('CustomerModelSession');
    if($customer_session->isLoggedIn()) 
    {
        
echo   "

".$customer_session->getCustomer()->getId();


echo   "

".$customer_session->getCustomer()->getName()";


echo   "

".$customer_session->getCustomer()->getEmail()";


echo   "

".$customer_session->getCustomer()->getGroupId()";

How do I add php variables from the session data above into the urlencoded.apend?

var urlencoded = new URLSearchParams();
urlencoded.append("email", "[email protected]");
urlencoded.append("tag_string", "VP");

urlencoded.append("first_name", "nate");
urlencoded.append("last_name", "davis");
urlencoded.append("addresses[0][address1]", "124 Main");

I’m assuming it’s just like this?

urlencoded.append("first_name", "<?php echo ".$customer_session->getCustomer()->getName()"; ?>");

Any help would be greatly appreciated.