No. Markup was removed as the storage method in version 4, several years ago. It is still used in a handful of admin areas. But not pages.
You can still type it, and the editor will recognise it and translate, but the data is not stored as markup, so pasting it in doesn't work.
You can also insert Markdown which will be automatically converted to Confluence format (and cannot be changed back. The reference is on the page you linked to:
I checked it on the latest version of Confluence Cloud and it is still there.
If you want to keep it in Markdown format, then I would recommend you use my plugin that Robert mentioned.
Badges are a great way to show off community activity, whether you’re a newbie or a Champion.Learn more
Hi Community, Jessica here from the Confluence Product Marketing team! July’s community challenge is all about sharing pictures — and as an extension of our first post on what ...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs