you shouldn't take only antiandrogens, your body needs one dominant sex hormone or you'll start having "fun" problems like loss of bone density. what you might be able to do is take a DHT blocker like minoxidil (the oral kind, ideally), which i think can sometimes affect facial hair growth? (pinging @gandalf_der_12te@lemmy.blahaj.zone)
that said, i do want to dampen expectations a bit - you shouldn't assume that any kind of HRT will necessarily affect facial/body hair growth. it can, but isn't guaranteed. i've been doing estrogen monotherapy for just over a year now and my body hair is still growing back exactly as thick and fast as it was before (facial hair is hard to say, it's 95% gone thanks to laser).
finally, i don't know how long you've been doing IPL but if you've been through many sessions and it isn't making a (significant) difference, it may be worth switching to a different studio which offers actual laser hair removal or even electrolysis.