how can i shwo values of database columns on telegram bot php?

Question

I made a code but it's not working it's showing this message Array ['premium'] instead of data.... my code:-

if(strpos($message, "/values") === 0){

$sql = "SELECT * FROM info";
$res = mysqli_query($db, $sql);

while($row = mysqli_fetch_assoc($res)){
    
sendMessage($chatId, "<b> $row ['premium'] </b>", $message_id);
}
}