HI Shuvajit Roy
Welcome to microsoft QNA!
You might be using the wrong option on Azure Migrate!
Basically you don't need a configuration server to migrate servers from Hyper-V, It's applicable in case of Physical and VMware environments.
The Microsoft Azure Site Recovery provider is installed on Hyper-V hosts, and registered with the Migration and modernization tool. The provider orchestrates replication for Hyper-V VMs.
Please "Accept as Answer" if this helps.