PHP using JSON string and inserting Data to URL [closed]

I have a php script that runs a API URL as below. Some of the information in the URL should be populated by echo information. Here is my current code.

$imei = $_POST['imei'];
$email = $_POST['email'];

$ch = curl_init("etrackfleet.com/api/api.php?api=server&key=256431&cmd=ADD_USER_OBJECT,<?php echo $email; ?>,<?php echo $imei; ?>");

curl_exec($ch);

Once I run the php file I get error Your browser sent a request that this server could not understand.

I presume the echo statement is not being read by the php request?

If I echo the $imei on the same page it shows the value from the POST but not in URL