Vault is not initialized in ha mode

i have deployed vault in azure cluster using the chart. I have enabled ha and raft in values.yaml. I have vault pods and an injector pod. vault pods are vault-0, vault-1 and vault-2. I have initialized vault-0 using vault operator init command and unsealed the vault-0 using the vault operator unseal command. now vault-0 is in ready state. Now when I try to unseal vault-1 and vault-2 using the unseal key obtained by running init comman din vault-- I am getting the following error.
Error unsealing: Error making API request.

URL: PUT http://127.0.0.1:8200/v1/sys/unseal
Code: 400. Errors:

* Vault is not initialized