Hi Jim,

this is outside the default scope of JSitemap, because you should modify links generated for Joomla contents accordingly to the plugin wbAMP Accelerated mobile pages for Joomla extension, so adding a final '/amp' to each URLs of that articles categories.

The only way to do this at the moment is using a template override and work at PHP level.

You can create an additional 'Content' data source, filter it by category choosing the desired one and create a dataset including that data source only. That dataset will be used only for AMP pages.
Finally in the template override you have to evaluate the ID of the data source and customize links adding the final '/amp'

If you have not PHP skills you can wait the next release, i can plan to add an option to manipulate articles links in the data source settings.

Regards

John