How to add a script in a phtml file

Question

I currently have a email pop up modal in my magento CMS but I need to hide the api so my script I will keep server side in PHP.

My question is how can I have a phtml that is just a script be imported into magento if that is possible.

this is my script

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://api.sendgrid.com/v3/marketing/contacts',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => 'PUT',
  CURLOPT_POSTFIELDS =>'{"list_ids": [
  "fsfsfsfsfsf"
 ],
 "contacts": [
   {
     "email": "[email protected]",
     "first_name": "jffff gih"
   }
 ]
}',
  CURLOPT_HTTPHEADER => array(
    'Accept: application/json',
    'Authorization: Bearer jhdfjhhueurheufheo',
    'Content-Type: application/json'
  ),
));

I omitted the api key and list id key for example reasons.