I'm using the next-sitemap package to generate sitemaps.

I wonder why exclude: ['/server-sitemap-index.xml'... doesn't exclude /server-sitemap-index.xml from sitemap.xml?🤷‍♂️🤔

I want two sitemap index files:
- domain.com/sitemap.xml
- domain.com/server-sitemap-index.xml

However currently I have:
- domain.com/sitemap.xml
- domain.com/next-sitemap.xml
- domain.com/server-sitemap-index.xml

Looks like this:

<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <sitemap>
    <loc>https://www.domain.com/sitemap-0.xml</loc>
  </sitemap>
  <sitemap>
    <loc>https://www.domain.com/server-sitemap-index.xml</loc>
  </sitemap>
</sitemapindex>

This is my next-sitemap.config.js:

/** @type {import('next-sitemap').IConfig} */
const siteUrl = process.env.NEXT_PUBLIC_SITE_URL
module.exports = {
  siteUrl: siteUrl,
  sitemapSize: 50000,
  generateRobotsTxt: true,
  exclude: ['/server-sitemap-index.xml', '/sitemap/*'],
  robotsTxtOptions: {
    additionalSitemaps: [
      `${siteUrl}/server-sitemap-index.xml`,
    ],
  },
  transform: async (config, path) => { 
    return {
      loc: path,
    }
  }
}

This is my /app/server-sitemap-index.xml:

import { getServerSideSitemapIndex } from 'next-sitemap'
import { getSitemapAmount } from '../mongoDbActions';

const siteUrl = process.env.NEXT_PUBLIC_SITE_URL
const maxSitemapLength = 50000 

export async function GET(request: Request) {
  const allCombisSitemapData = []

  const numberOfSitemaps = await getSitemapAmount(maxSitemapLength)  

  for (let i = 0; i < numberOfSitemaps; i++) {
    allCombisSitemapData.push(
      `${siteUrl}/sitemap/${i}.xml`
    )
  }

  return getServerSideSitemapIndex(allCombisSitemapData)
}