Yes you can. You can also put the ammonia in without the filter start. The results will be very similar.
At the top of this forum section is a link to the Beginners Resource Centre. Click on that, and then click on the link to Fishless Cycling. I suggest you use the Add & Wait method.
Since you already have the Filter Start, you may as well use it, but many forum members have no faith in most of these products. I used a different product claiming to do much the same thing, and found it made no appreciable difference.