How to submit blogger blog sitemap to google webmasters tools

To get more search traffic on your blog, it is necessary to submit your blog's sitemap to google webmasters tool. But to submit blogger blog sitemap, we need an xml file of the sitemap and have to upload it in the root directory of the domain. But for blogger, it is not possible to upload a custom sitemap.xml file with the domain because blogger doesn't offer to host external files and that's