Before sending request for your custom domain, You need to add CNAME records (given in below table) in your custom domain from your domain registrar account (like - namecheap, godaddy etc...).
 CNAME records are needed to point your custom domain to our domain ( nazmart.net ), so that our website can show your website on your custom domain
 Different domain registrar (like - godaddy, namecheap etc...) has different interface for adding CNAME records. If you cannot find the place to add CNAME record in your domain registrar account, then please contact your domain registrar support, they will show you the place to add CNAME record for your custom domain. They can also help you with adding CNAME record for you.