请问:手印是单独一封信通知，还是按485收据上的通知预约？
律师和朋友讲是单独一封信通知，但在我刚刚收到的485收据上（TSC）有这样一段话：
If this receipt is for an I90, I485 or I698 application Biometrics - (fingerprint, photo, signature)
The next step is to have your biometrics taken at USCIS application support center(ASC). Call customer service at 1.800.375.5283 to schedule your apartment……
What to bring to your appointment.
You must bring this letter and a photo identification to you appointment……
说要自己打电话去联系biometrics，不过没有说ASC code (1,2,or3)。是新的规定吗？哪位朋友解释一下，谢谢。