Where and who should register the PTR record?

Question

Domain Name System

Raised the mail server on CentOS. postfix+dovecot+dkim. Everything works great. But only on all other services they get into spam. And then it dawned on me to check the PTR, empty.
I have internet from an ISP with static. I take the domain from the hoster (hoster.kz), DNS is also from them.
Now the question is, who should prescribe PTR?
1. Provider in your DNS?
2. A hoster that provides me with a domain and DNS records? (I can only create A, AAAA, MX. CNAME, SRV, TXT records in the DNS management office.
3. Am I on the server?

Answer 1

PTR indicates the owner of the IP addresses. Contact your ISP or hoster (in case of vps)

Answer 2

The provider must register that rDNS matches HELO. Your domain does not have to appear there, usually some subdomains of the provider

Answer 3

Whoever gave you the IP must have it registered.