Difficulty: Any
Location: Bill's Town - High School Escape
After the fight with the Bloater in the High School, you'll follow Bill and Ellie to a house to which you have to climb over a fence to get to. Ellie will then discover a pickup in the garage that has a dead battery. Once the cutscene is over with, you're encouraged to look around for supplies. You'll have the option to pickup the Optional Conversation with Ellie as she sits in the driver seat. You'll then make your way towards the opposite end of the house where you will find Artifact #26 - Note From Frank. Once you're done collecting that and whatever supplies, make your way back to the garage and pickup another Optional Conversation where you will hand the note to Bill. He'll then crumble it and toss it to the side. Walk around the pickup truck from the back and pickup said crumbled note. The trophy should pop then.