The Flickr Photo Album ID is located at the end of the URL after you have clicked on a Flickr Album. It will be a series of numbers located in the same place in the URL where the "XXXX" is located in the sample URL below.
(DO NOT paste the entire URL address. Only paste the numerical Album ID located at the end of the Photo Album URL)***If you get this error: “Invalid set id / album not found!”, that means that you need to change the below listed setting in your Flickr account.