Have you tried AMS Web Sign In yet? It will connect you with all your reviewer information and fill in parts of the submission page for you. If you are creating your AMS Account for the first time, be sure to add your reviewer number to your profile.

The MR Number of the item you will be reviewing is the seven-digit number appearing directly below the MR address in the upper left hand corner of the review sheet you received by postal mail. (The leftmost seven numerical digits, if there are more than seven characters.)

Your reviewer number contains six digits and appears below and to the left of your name on the review sheet.

Items marked by an asterisk * are required.