Gateway sms Skebby

Good morning everyone this is my second forum post, I am a beginner and I am trying to implement an SMS gateway with skebby in my app but I probably miss some programming fundamentals, someone could explain to me what is the right way to go thanks
the first block works but the second does not, I practically wanted to read the mobile number from the db through a query but I am not succeeding, thanks to everyone for a possible answer

first working block:
$ smsSent = sendSMS ($ auth, array (
“message” => “Hello world!”,
“message_type” => MESSAGE_HIGH_QUALITY,
“returnCredits” => false,
“recipient” => array ("+ 393669783426"),
“sender” => null, // Place here a custom sender if desired

));

if ($ smsSent-> result == “OK”) {
echo ‘SMS sent!’;

second block not working with cell number reading from db:
$ smsSent = sendSMS ($ auth, array (
“message” => “Hello world!”,
“message_type” => MESSAGE_HIGH_QUALITY,
“returnCredits” => false,
“recipient” => array ("{{lista_preventivi1_unico.data.lista_prev1_unico [0] .num_sms}}"),
“sender” => null, // Place here a custom sender if desired

));

if ($ smsSent-> result == “OK”) {
echo ‘SMS sent!’;
}

?>