It needs to be on the server itself, it wouldn’t be through DNS. Your “hosting provider” (might also do your DNS, but might be separate) is where to look to see if it has server access available at all. If they provide you a full blown CMS (content management system) and never obviously offer server access then you might have to ask their support team. They likely can drop a file in if you need it. This file (format in that article) has nothing but public info and the point is to post it publicly, so you don’t have to worry about chain of custody or anything.