You will need to create an account on Bounty0x to participate, it only takes a minute and you can sign up as a Hunter here: https://beta.bounty0x.io/register. The usual account setting-up process i.e. name, username, password etc. You will be asked to confirm your new account by email.
Bounty0x will also ask you for an ETH address. Please add this as the LUMA tokens will be distributed after the end of our public sale and released via the Bounty0x platform for transparency and accounting.