When I add NS (alone) from DigitalOcean suggested by every tutorials, error “ERR_NAME”
When I add NS then A record, I can’t (showing by the uploaded image)
When I add A record (alone), it does redirect but showing the IP which I does’nt want.
Sorry for this rookie question, I’m missing something ? Do I need to configure Digital Ocean’s side aswell ?
By hosted you mean the A records point to the provider in question, correct?
Your main domain does point to Cloudflare right now. The question is what do you want to do with blog. Should that just point to an IP address or should be a subdomain, where you can delegate further host records (i.e a.blog.DOMAIN, b.blog.DOMAIN etc.)?
Alright, then you create an A record pointing to that address (optionally you can proxy it with if you want that)
Thats not a DNS issue though, but an HTTP one. The server at that address simply sends a redirect to the address. That could be either because of a missing virtual host or some other configured redirect and is something you need to fix on that server. DNS is unrelated in this context.