One of the Battle Pass Challenges in Fortnite Season 8 Week 10 involves killing people and Volcano Vents. This is one of the challenges that requires full combat, not only do you need to actually find and use the vent, but you have a very strict time limit in which to do it in.
The trick is to make sure you have a strong weapon and ideally one that does well up close. A shotgun is a very good choice here. It isn't enough to simply do the jump and land, you ideally need to be able to take out the people also trying for this challenge. A shotgun will let you deal with the close-range nature of the combat around the Volcano Vents.
The Volcano Vents themselves are all located near the volcano in the top-right of the map. The geyser field to the north of the volcano has a fair few of them and if you look just to the south of the volcano itself you can also find an awful lot. This is likely to be the most popular spot, just make sure you're ready for the fight.
It is worth taking this challenge on in Team Rumble rather than alone, it just makes things simpler. Going it alone is obviously an option if you're confident, but if you are still a little nervous then being with a group should make it easier, though probably a little bit slower too.
Your positioning is key too and if you land in front of someone then they're likely to see you coming. If you keep an eye on the ground and try and land behind someone before shooting you'll have a much easier time of things.
Check out the map below for a general idea of where the vents can be found and the best spots to do this challenge as a result.