I don't agree with you.

There was no any security at the door. The place I went was not the place most people go for EAD or some other stuff.

I think there won't be any problem. The guy at the front dest will ask you to fill out a form. Then he put your notice with that form you filled together. Then you are able to wait for your turn to have the FP collected. Within several hours, your FP result will be in INS' data base