I set up a similar environment for my storage account by creating it using the CLI.

az storage account create --name mystoragecdnbab --resource-group anji-rg --location centralindia --sku Standard_LRS --kind StorageV2  

Then i enable static website to my storage account

az storage blob service-properties update --account-name mystoragecdnanji --static-website --index-document index.html                                

Then I created DNS profile

az cdn profile create --name mycdnprofile --resource-group anji-rg --location centralindia --sku Standard_Microsoft

Then I created DNS endpoint

az cdn endpoint create --name mycdnendpoint --profile-name mycdnprofile --resource-group anji-rg --origin mystoragecdnbab.z29.web.core.windows.net --origin-host-header mystoragecdnbab.z29.web.core.windows.net

I added dummy index.html file to my setup got access in web using DNS endpoint https://mycdnendpointbab.azureedge.net/

In your case, since you have another domain name, you need to add that domain name to access your service on the web. To do this, you should map Azure CDN to your custom domain like cdn.domain.com, ensure that you have a valid domain since you already purchased from Namecheap. In your DNS provider, add a CNAME record for 'cdn' pointing to your Azure CDN endpoint like mycdnendpointbab.azureedge.net. Once DNS propagates, validate this custom domain in Azure CDN Profile under 'Custom domains' section. This will allow traffic to cdn.domain.com to be served via Azure CDN.

Similar issue: Azure FrontDoor CDN Classic add custom domain Please let me know how it goes. -Thank you @Nicke Manarin