Looks like it should be sweet enough already from the ingredients. IPAs are generally dryer than APAs. I don't know any details, but would suggest you consider not messing with it.
What was your FG? I like my FGs for IPA to be 1.010 or lower.
If you must sweeten a beer ...... although I consider it to be sacrilegious, you can add some lactose at bottling. Boil it with the priming sugar. Lactose is non-fermentable. Use with restraint as it can get too sweet quickly. 2 ozs will increase the gravity of a 5 gallon batch by .001.