smash.gg is only the platform that helps with tournament activities; we do not actually run any of the events ourselves unless specified in the tournament details (For example: The Recruit Grinder Tournament Series). All registration fees go straight to the tournament organizers and they are responsible for paying out the winners.
Regarding payouts, please reach out to the tournament organizers directly by going to the bottom of the smash.gg tournament page you registered towards and accessing the contact information they provided.
Here is an example of where the Contact field would be located (if applicable)
In the event the organizers haven't provided any contact information, feel free to contact us at email@example.com so that we may assist you further in finding contact information!