Your Nintendo Friend Code is how players will be able to add you to their friends list. To find your Friend Code:
1. First, start at the Switch home screen and select your profile from the top left of the menu.
2. Your Friend Code will be displayed on your 'Profile' as shown here.
Now that you have your Friend Code, you can enter it when joining to the tournament (remember to input the code as shown on the Switch, including the SW and dashes).