Its complex. Basically when bidding for contract, SpaceX was able to submit a whole list of milestones. Each milestone is associated with some amount of money.

Its complex. Basically when bidding for contract, SpaceX was able to submit a whole list of milestones. Each milestone is associated with some amount of money. NASA and SpaceX together negotiate these milestones and the associated payments in the contract negotiation. Since this is a contract for a moon lander, and not a rocket, the launch itself is only a small part of the money. So a successful launch to orbit is very mostly likely to be one of these milestones. Successful reentry is another potential candidate. So if successful it would result in some payment from NASA, but since we are talking about a moon lander, launch will not be the primary milestone. We don't know the list of milestones, that secret between NASA and SpaceX. But things like doing orbital refueling, landing on the moon are likely the most important milestones. Its pretty certain that if they don't reach orbit, they will not be able to clear any milestones and thus not receive any payment. Unless they have some milestone for things like stage separation, but that sound unlikely.