need answer about vermont

how long would it take for me to have my ATT? i sent the return post card a week ago and is expected to arrive in vermont in just 3 days. how long would it take for me to have my ATT when they already received my post card?

anyone who knows about this, please answer me. i am planning to have my exam on the first week of september but i can't schedule an appointment yet with pearson vuie for the exam because i dont hjave the ATT yet...