I have to spot feed my ABF and he now swims out to the middle of the tank to greet me, expecting his share of food (Prima Discus)!
It might take a few days for confidence to build up, but hold your hand containing a single pellet or flake at a time about five inches above the tank. Drop the single bit of food right in front of your ABF, even then they may miss a few, but mine got much better with practice.
If this works, you might want to give him ~10 bits of food, partly to sort out its hunger, but also ingrain a conditioned response to your hand being near to him/her and that it is good as your hand brings food (like Pavlov's dogs experiment, http/en.wikipedia.org/wiki/Ivan_Pavlov)
But given its been two weeks with no food, I would not try in vien for too long. If he/she has not eaten in the next day or two, perhaps some small live crickets or mealworms will at least get your ABF eating (but don't get it used to live only, mix in plenty of dry food)