You can do it within 90 days after your date
situn,
I am not sure which FP office you will be going to but when we went to the Atlanta office they told us that if a filer is unable to make it to an appointment, they can get their FP done anytime within 90 days after the date of the notice. This is what they told us. I am not certain if it is correct or not. Try going to the office and they will probably take you in.
regards,
saras