a php telegram bot in insert value in table

Question

I am trying to insert some value in a table. but it does not work! how can I fix the problem? here is my code:

$servername = "localhost"
$username = "****"
$password = "****"
$dbname = "****"
$conn = new `($servername, $username, $password, $dbname)
$sql="INSERT INTO d(id, server)` 
VALUES ('****', '****')"
$conn->close()

insert values in a table