Hi, @Siddharth. We have a support guide about how to find this information here:
To summarize, make the change in the web UI and the network tab of devtools will contain the working example of the API call.
I believe you are trying to get this API call working:
https://open-api.netlify.com/#tag/dnsZone/operation/createDnsRecord
If so the zone_id is the domain name name delegated to Netlify changed into “slug format”. To summarize, you cannot have a “dot” (the character .) in URL path segment (which is where this zone_id is found) so the dots must be changed to underscores (_).
If your domain name is example.com the zone id in the slug format is example_com.