My application on Azure consists of a Storage Account, Cosmos DB, SQL Server, a Web App, and a Function App. The Private Endpoint needs to be set up and used. Every type of Private Endpoint requires a dedicated Azure Private DNS.
eg:
Is it necessary to have dedicated Private DNS for each resource type like file, blob, table, Cosmos, and SQL? Can't I use the same Private DNS for all type of Private Endpoints?
Yes, it is necessary and you will need a separate Private DNS Zone per resource type.
See Azure services DNS zone configuration for details.
However, you can re-use the same zone across regions and subscriptions, so you should only need them once within your Azure tenant.