Nameserver with ip adress

I have domain what registed with crezydomain.in
When I try to update my nameserver … There are requirements for ip adress too…
Anyone can help me how I can update my nameserver… Because I have not ip adress …Only nameservers from cloudflare…

Are you sure you are updating the nameservers in the right place? Typically - and technically - one does not need IP addresses in this case.

There are some obscure registrar who still require it (for whatever reason) and in these case simply use the IP addresses of the respective hostnames of the nameservers -> resolve the IP address of each hostname given to you.