I deployed the dotnet core application using the connection string. I couldn't access external DB after I deploy the dotnet core app in Kubernetes Pods.

The site shows below error:

SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 40 - Could not open a connection to SQL Server)

Can you please help me?