Find one using a flying tame with high-ish health. Once you find one, consume a rare flower and it will attack you. Kite it to a safer area or a taming pen while continuing to consume rare flowers. Be prepared to bola the tappy once at desired location, it can be tricky trying to bola a tappy when it is attacking.
Extremely difficult to tame. Best options are to bola it, and then use a longneck rifle with tranq darts. Otherwise trying to get it to fly into the side of a cliff and get stuff is the other option for a solo tame.
Since the new update, rare flowers make dinos aggro on to you, you can use this on a tapejara and it will follow you to a trap you've built. Just remember that each flower gives only 10 seconds of that debuff so if the bird is far away from your trap, you have to use it frequently while coming back. Also, if you need it to follow you after you've gotten off your dino, you need to eat another rare flower so that it can agro on to you once again.