Hi i dont understand... you can do it yourself, don't modify the real .xml file.
why this app ? it's for beginners thank you but its not for me just a link : https://venazone.com/tools/sitemap

Cette application est juste parfaite et le support technique est à l'écoute et très réactif. Je recommande vivement!

The app is easy to use and does what it says. The support team was very responsive and helpful. The only negative is that you can not control which collections are shown, and it will only show up to a certain number of collections. We have a lot of auto-collections created for our filter menu (size, price, etc.) and many of them do not need to be displayed due to duplicate content (or no content). It would be great to not include those in the HTML sitemap. With the products, they display a certain number along with a "next page" feature at the bottom of the list to view the next set of products. If the collections could offer this same display, I wouldn't mind them including all of our auto-created collections. It is a bummer that most of our important collections are not seen because so many price and size collections show at the top. I have brought this to their attention and they were understanding, helpful, and nice. Hoping they will release an update and we can install the app again. I really did like the column layout and simplicity.