Hi Raghu,
Do you have vcenter for the ESXi as management layer or no ?
if the esxi nodes are managed by vcenter, you can use agentless method to migrate the VM.
if the esxi nodes are standalone and no vcneter, \ you can treat your VMware VMs as physical servers and use the agent-based migration workflow.
refer the FAQ on azure migrate for more details:
https://learn.microsoft.com/en-us/azure/migrate/common-questions-server-migration