I want to set up a server on an old laptop at home to synchronize my Obsidian notes and some pdfs. I'll install Nextcloud AIO but I have a question about domain.

Do I need to buy a domain name for the sync to work properly? I created a dynamic dns account on Noip but I don't know if this is a temporary solution or permanent?

If the domain is necessary, is it enough to just buy a domain or do I need to buy a hosting package or something?