How does your app generate the sitemap? Show us some examples. With: https://github.com/kjvarga/sitemap_generator In Rails you may need to define a route, controller action and xml view for your sitemap controller , such as:
def sitemap
respond_to :xml
expires_in 123_456, public: true
end
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<sitemap>
<loc><%= "SITEMAP_UPLOAD_HOST/sitemap.xml.gz" %></loc>
</sitemap>
</sitemapindex>
Where SITEMAP_UPLOAD_HOST may be AWS S3. You can configure the rest in config/sitemap.rb in Rails