Sitemap urlset http or https [duplicate]

I am a Static User I write my all pages and sitemap with pure html css code, I have a question that in sitemap I am using http xmlns in order to make my sitemaps so is it allowed to add https or http is better that’s why all are using it.

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9 http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd"> 

So in the above I would like to ask that is it allowed to use https xmlns?