Google search console accepts sitemaps hosted on the domain of the site in Google Search Console. Could you please allow uploading XML sitemap files to the file manager or in a theme so we could improve visibility in search for videos and images? Or better yet, auto generate these for us instead of having to use a third party tool.
Here is related community post.
https://community.hubspot.com/t5/CMS-Development/Video-Sitemap/m-p/742727