IoT Button for AWS Gateway setup

When trying to set up the AWS IoT Core Gateway, I am trying to use the device’s id/bar code number as the Gateway EUI, but that is not working. I have tried formatting it every possible way - with colons, with dashes, all uppercase, all lowercase. Nothing works! I can’t use this device if I can’t get past this simple step & the user instructions don’t offer any additional information.
Any help or guidance appreciated!

Please disregard my earlier post. I misunderstood the instructions, but now have it working through AWS IoT 1-Click.