For one of the "Week 6 Resistance" Quests in Fortnite Battle Royale Chapter 3 Season 2 you need to "Eliminate IO Forces to Steal IO Credentials" and then "Deliver IO Credentials to the Imagined near the Joneses".

You can find IO in many places around the map, especially at areas where there are battles going on. An easy place though which you can always find IO Forces at is the Fortress. Once you have the credentials, bring them to the Imagined to complete the quest.