I have a Next JS application which was built using Next 12 and I am migrating it to Next 14. I have multiple sitemaps indexed in google earlier. Now I am trying to migrate them to App router logic. In my project I have a sitemap with folder path as pages/sitemaps/[categoryId]/category.xml.tsx which was accessible in the path https://localhost:3000/sitemaps/124/category.xml. I want to maintain the path of the sitemap in my app router as well. I created file app/sitemaps/[categoryId]/category/sitemap.ts to keep the exact same path.
Here is my code:

//app/sitemaps/[categoryId]/category/sitemap.ts

import { MetadataRoute } from 'next';
export default async function sitemap({ params }: { params: { categoryId: string } }) : Promise<MetadataRoute.Sitemap> {
    console.log("Params: ",params);
    const categories:ICategory = await categories(parseInt(params.categoryId));

    return categories.map(category => {
        return( {
            url: `${SiteURL}${getCategoryLink(category)}`,
            lastModified: new Date(),
            changeFrequency: 'daily',
            priority: 1,
          })
    })
}

When I tried the link https://localhost:3000/sitemaps/124/category.xml, it shows 404.
When I try the link http://localhost:3000/sitemaps/124/category/sitemap.xml, it is showing error that “Params not found”. My dynamic route path is not accessible inside the files, my params value shows undefined.

1. Why does the dynamic param is not accessible inside the file?
2. Does the end path have to be [...]/sitemap.xml always? Can’t it be any other name ?