When i tried to add a Label under the “Information management settings” inside my Site content type i got the following error "The label reference, Version, could not be found"

I want to show the document versions inside our sharepoint online document libraries' items. so i follow these steps, which show how we can add a Label inside our document list content type:-

https://blogs.msdn.microsoft.com/chhopkin/2014/02/24/showing-the-document-version-number-on-a-visio-document/

and this worked well, where i was able to add the {Version} label to my document list content type. but since we have many document libraries, so i want to set the {Version} label on the Document site content type and not on the Document list content type  (as shown in the above link). but when i try adding the {Version} label to my Document site content type i got this error :-

"The label reference, Version, could not be found"

so not sure why i can add the {Version} label to my list content type while i can not do the same for the site content type? as doing this on the site content type which will allow me to update all current and future lists at once..