Where do I find groupID, referenced by a dynamic group query?

This article details how to configure a dynamic group using the new memberOf query, and says that in the syntax to use the groupID for the relevant groups. I've done some digging online but nowhere is specifically saying what the groupID actually is.

When looking at a Security Group on Azure, I have the objectID and I wonder if this is the same thing? Naming them two different things makes me believe they are not cross compatible though.

Any help is much appreciated. If this isn't the best place for this query please direct me to where I should be asking.