Duplicated here:
https://storejextensions.org/forum/view/10-jsitemap/6033-re-missing-select-option-on-data-sources.html

After creating a second 'content' data source you can use it only for the RSS feed and exclude certain categories as you prefer. Having 2 'content' data sources allows you to use one for the regular XML sitemap but not for the RSS feed, and on the contrary use the other one that includes only a subset of categories for the RSS feed only. This is done through buttons to enable each data source for various formats:



As an alternative you can even use datasets to create multiple RSS feeds based on different data sources. To learn more about datasets usage refer to the PDF docs at the paragraph 'Datasets'.


Regards