Create a database subdomain sitemap index using default .env

[grafxflow]

I have several subdomains listed in a database, but when indexing the files listed are using the env default. Is there anyway I can insert the subdomain of the index.

foreach ($sites as $site) {
    SitemapIndex::create()
    ->add('/' . $site->subdomain . '-pages_sitemap.xml')
    ->add('/' . $site->subdomain . '-posts_sitemap.xml')
    ->writeToFile(public_path($site->subdomain . '-sitemap.xml'));
}

<?xml version="1.0" encoding="UTF-8"?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
    <sitemap>
        <loc>https://website.com/subdomain1-pages_sitemap.xml</loc>
        <lastmod>2022-04-24T15:53:14+01:00</lastmod>
    </sitemap>
    <sitemap>
        <loc>https://website.com/subdomain1-posts_sitemap.xml</loc>
        <lastmod>2022-04-24T15:53:14+01:00</lastmod>
    </sitemap>
</sitemapindex>

When I want.

<?xml version="1.0" encoding="UTF-8"?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
    <sitemap>
        <loc>https://subdomain1.website.com/subdomain1-pages_sitemap.xml</loc>
        <lastmod>2022-04-24T15:53:14+01:00</lastmod>
    </sitemap>
    <sitemap>
        <loc>https://subdomain1.website.com/subdomain1-posts_sitemap.xml</loc>
        <lastmod>2022-04-24T15:53:14+01:00</lastmod>
    </sitemap>
</sitemapindex>

[grafxflow]

I have found this way so easy enough.

foreach ($sites as $site) {
    SitemapIndex::create()
    ->add('https://' . $site->subdomain . '.website.com/' . $site->subdomain . '-pages_sitemap.xml')
    ->add('https://' . $site- subdomain . '.website.com/' . $site->subdomain . '-posts_sitemap.xml')
    ->writeToFile(public_path($site->subdomain . '-sitemap.xml'));
}