Hi Phil,
Azure Migrate appliance isn't used for Hyper-V migration. for migrating Hyper-V VMs, the Migration and modernization tool installs software providers (Microsoft Azure Site Recovery provider and Microsoft Azure Recovery Service agent) on Hyper-V Hosts or cluster nodes.
So you will need both the agents for replication and migration and also this document provides detailed steps on setting up the HyperV migration process - [https://learn.microsoft.com/en-us/azure/migrate/tutorial-migrate-hyper-v?tabs=UI
Hope this helps.
JS
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