通过PHP在远程服务器上执行JAR

I have a remote linux server, that contains a jar file, that I would like to be able to open. Its path is /home/files/java/exec.jar.

I tried executing it through PHP, and I needed to put it in the folder /var/www/html/run_jar.php.

Here is the code I achieved:

<?php
$path = '/home/server/spigot-1.13.2.jar';
$exists = file_exists($path);
if($exists){
    echo 'File exists, running...<br>';
    $msg = shell_exec('java -jar '.$path);
    echo '"'.$msg.'"';
} else {
    echo 'File doesn\'t exist';
}
?>

However when opening the php on google chrome, it says the file doesn't exist, when it clearly does. Are there any permission I should be aware of? And how would I manage to actually run the jar on the remote server? Thanks!