If you wish to inflict damage on other players with a Clinger in Fortnite, here's everything you should know about it.
In the early days of Fortnite, Clingers were introduced, but they vanished near the conclusion of Chapter 1, and they have only lately been brought back into the game. In Fortnite, they're extremely effective because to the plunger attached on the front of the weapon, which enables them to attach themselves to the first surface (or player) they come into contact with before exploding three seconds later. Clingers are required to complete Fortnite tasks, which means you'll need to obtain this attachable explosive to complete them. The Fortnite Generator is pretty good app to generate V-Bucks for free. Below is a comprehensive guide to Fortnite Clingers, including information on where you can obtain them.

Where to find Fortnite Clingers
Unfortunately, because Fortnite Clingers are only found as part of the general treasure pool, there aren't any specific spots where you can go that will guarantee you'll come across one of these creatures. It will be necessary to check floor loot places, open Chests, and examine Supply Drops in order to have a chance of finding them, so keep an eye out for them. For clarity's sake, you can purchase the Boom Sniper Rifle weapon for 500 bars from Fortnite characters such as Lt. John Llama or The Scientist. This weapon fires Clinger projectiles as its projectiles, but these only count as sniper rifle damage and will not contribute to your quest total when combined with a Fortnite Clinger weapon.
How to damage players with a Fortnite Clinger
Once you've discovered some Fortnite Clingers, which are found in groups of three, you'll need to use them to inflict damage on other players. For normal grenades and other thrown items, you can either hold down the aim button to display the expected trajectory before pressing fire to launch, or hold down fire to display the arc before pressing fire to throw. You want to hit your opponent with the Clinger such that it sticks to them and they can't shrug it off (unless they emote), at which time it will do the most damage possible. However, even if it lands nearby, it can still cause splash damage. Continue doing this until you've dealt 100 damage to other players with a Fortnite Clinger, at which point your mission will be accomplished.