When sending and requesting funds from Sling Money users, you can choose if you want your name to be visible in the Sling Directory or not
Step by step
To manage your visibility in the Sling Money app:
Tap your avatar at the top left of your transaction screen
Tap 'Directory'
Then, you will have the option to let Sling Money users find your username on the search bar or not, by clicking the toggle button.