• Most items from ASD that require avatar keys will include an object named "Key Finder" in the original box. (If you do not have it you can get the script here and copy it to a New Script in-world in a New Object.)
• Rez the object in-world and have the avatar Touch (click on) it. It will say the user's UUID key in Chat.
• Open your Local Chat History [ctrl+H] and Copy the key.
Here's an example of a valid key: 33d19ef6-bfcc-468a-ba4c-ba7a9130cd0e