static, dynamic and external maintained sitemap configuration

[RishikeshDarandale]

I have two questions as below:

• How to configure the externally managed sitemap with this plugin?
  Say, I am migrating the application and few paths are maintained by another application. Thus, an externally maintained sitemap needs to be configured only in robots.txt as below:

# new sitemap from nextjs application - index sitemap
Sitemap: http://localhost:3000/sitemap.xml 
Sitemap: http://localhost:3000/sitemap-old.xml

When I add /sitemap-old.xml to robotsTxtOptions.additionalSitemaps configuration, it adds this entry in robots.txt and index sitemap.xml as well. It should just add it to robots.txt

• With above configruation, I have dynamic sitemap as well. When I declare it(as shown below), it adds dynamic sitemap-d1.xml to robots.txt and sitemap.xml (index sitemap as well). Here, it should be added to sitemap.xml only.

/** @type {import('next-sitemap').IConfig} */
const config = {
  // base url of the application
  siteUrl: 'http://localhost:3000',
  exclude: [
    '/404',
    '/sitemap-d1.xml',
  ],
  generateRobotsTxt: true,
  robotsTxtOptions: {
    policies: [
      {
        userAgent: '*',
        allow: '/'
      },
    ],
    additionalSitemaps: [
      // legacy sitemap
      'http://localhost:3000/sitemap-old.xml',
      // Dynamic sitemap
      'http://localhost:3000/sitemap-d1.xml',
    ],
  },
};

module.exports = config;

//sitemap-d1.xml.tsx
import { getServerSideSitemap, ISitemapField } from 'next-sitemap';
import {
  GetServerSideProps,
  GetServerSidePropsContext,
  PreviewData,
} from 'next';
import { ParsedUrlQuery } from 'querystring';

export const getServerSideProps: GetServerSideProps = async (
  ctx: GetServerSidePropsContext<ParsedUrlQuery, PreviewData>
) => {
  // TODO: get all dynamic paths 

  const paths: ISitemapField[] = [
    {
      loc: 'http://localhost:3000/path1',
    },
  ];

  return getServerSideSitemap(ctx, paths);
};

// Default export to prevent next.js errors
export default function DSitemap() {
  return <></>;
}

I am expecting below:

// robots.txt
Sitemap: http://localhost:3000/sitemap.xml
Sitemap: http://localhost:3000/sitemap-old.xml

// sitemap.xml
Ref to sitemap-0.xml // static paths
Ref tp sitemap-d1.xml // dynamic paths

Please let me know if this is possible @iamvishnusankar .