dt is real money that are put in the server, donation tickets(dt) cost 1 dollar each, with that, you can upgrade your items, buy items from others players. DT can only be used in forum. the difference to PD is that pd can be used direct ingame for trades and can be found in quests, while dt not. if by chance you will use dt, by getting some for you stuff or by donations, you can track that easy if you press your photo profile.
about donation itself, i cant help you on that, since i never make it, but i know that besides official forum link for donation, you can contact LARVA for alternate ways to donate and get those DT