Part 1. Setting Up the Dash Button
Getting your Dash button ready for hacking is pretty straightforward - you just need to go through the entire Amazon setup process minus selecting a product.
This setup requires the Amazon app, which is available for iOS and Android. Once logged in to Amazon inside of the app, go to Your Account -> Set up a new device. Select "Dash Button" and follow the instructions until you are prompted to select a product.
Close the app. Don't cancel setup; don't hit the x - just close the app. If you accidentally selected a product or are repurposing an old Dash button, just remove the device through the Amazon app and follow these steps again.