<?php

include("db.php");
$user = 'user';
$password = 'pwd';

$script = '/my/path/to/script/script.sh';

...

$testResult = mysqli_query($dbConnection, $queryNextTest);
$test = $testResult->fetch_object()->test_script; //this is my parameter obtained from query

$stream = ssh2_exec($connection, $script); //how can I use test as my paramter to execute the

?>

$stream = ssh2_exec($connection, "/my/path/to/script/script.sh {$test}");