I used a sitemap generator gem, it created a sitemap.xml.gz (after I installed the gem and ran the ruby script)
I added this file to google search console, but it doesn’t like it. It says, your Sitemap appears to be an HTML page. Please use a supported sitemap format instead.
Perhaps this issue might better be brought to the gem, they might have an idea? Or perhaps a site such as StackOverflow might be better place to get answers to debugging questions such as these? Good luck finding your answer!
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