I have a website which has a lot of dynamic pages (similar to top.gg where each user can add a bot to their website and then they have a page for the bot). I was looking at top.gg's implementation of their sitemap, and it looks like they create a sitemap for every x bots. I'm wondering how I could achieve something similar, where I create a sitemap for each of mine (there will be around 1,000,000 of these pages so I can't put them into a single sitemap)

Here is top.ggs : https://top.gg/dynamic-sitemap.xml
I'm using nextjs app router v14.2.6