You have to invest some of your HP by a delegation to the account or you can buy tipu tokens that get part of the payout on the project. There is no way to buy a vote. It is about investing together into the account to build a whale. Then they pick people to give out the votes.

You can see us here. https://tipu.online/hive_curators

I am allowed to curate my own stuff but only a little. I only support my alts that giveaway splinterlands cards and my 3speak videos I make then I give all the other votes to others.