How can I change my dynamic XML file structure in Next.js?

I have successfully created a sitemap in Next.js by generating dynamic links in an XML file that look like the code below. I tried to use the same methode to create an XML file that I can submit to Pinterest but they rejected the file because the structure doesn't match theirs. I have no clue how to do this. I want to replace urlset and url by channel and item. Also I'm not sure what are those g:x tags but I don't this this matter that much. How should I do this?

my XML file in /pinterest-products-sitemap/index.tsx :

import { getServerSideSitemap, ISitemapField } from 'next-sitemap';
import { GetServerSideProps } from 'next';
import { 
   getProducts,
} from '../../components/Utils/apis';
import { 
   productsPage
} from '../../components/Utils/pageUrls';


export const getServerSideProps: GetServerSideProps = async (ctx) => {

    const resProducts = await fetchAPI(getProducts);
    const dataProducts = await resProducts;


    const result = []


    dataProducts.map(product => 
        result.push({
            link: `${process.env.FRONT_END_URL}${productsPage}/${product.slug}`,
            id: product.id,
            title: product.name,
            description: product.seo && product.seo.meta_description,
            image_link: product.poster && product.poster.url,
            price: product.price.toFixed() +'.00' + ' EUR' ,
            availability: 'In Stock',
            isDigital: product.isDigital,
            brand: 'The brand',
        })
    )

    return getServerSideSitemap(ctx, result)
}

export default function Site(){}

example of my returned XML:

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:news="http://www.google.com/schemas/sitemap-news/0.9" xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:mobile="http://www.google.com/schemas/sitemap-mobile/1.0" xmlns:image="http://www.google.com/schemas/sitemap-image/1.1" xmlns:video="http://www.google.com/schemas/sitemap-video/1.1">
   <url>my-product-slug</link>
    <id>9</id>
    <title>Product title</title>
    <description>Just some content</description>
    <price>45.00 EUR</price>
    <availability>In Stock</availability>
    <isDigital>yes</isDigital>
    <brand>The Brand</brand>
   </url>
</urlset>

example of what Pinterest want:

<rss xmlns:g="http://base.google.com/ns/1.0" version="2.0">
  <channel>
    <item>
     <g:id>4000086</g:id>
     <title>Illuminating Makeup Mirror</title>
     <description>A ring light mirror with 23 LED strip lights.</description>
     <link>https://www.example.com/cat/illuminating-makeup-mirror</link>
     <g:image_link>https://www.example.com/media/catalog/product/image.jpg</g:image_link>
     <g:availability>In Stock</g:availability>
     <g:price>14.99 GBP</g:price>
     <g:price>0 GBP</g:price>
   </item>
  </channel>
</rss>