May B
If you are referring to the World of Hyatt membership number, all you have to do is log into your Hyatt account and it will give you the membership number as well as the effective membership date. It will also show you your status such as Explorist, Globalist, etc. If you are using a Mac as I was, follow these directions to paste a screenshot of your membership to the MSC application form:
Press Shift-Command-4, then move the crosshair pointer to where you want to start the screenshot. Press the mouse or trackpad button, drag over the area you want to capture, then release the mouse or trackpad button.
Hope this helps.