Hi @Varma ,
please take a look here: Use Azure Key Vault to pass secure parameter value during deployment
If you like to use secret values using a Key Vault in Azure deployments these options need to be activated.
Some more information: Tutorial: Integrate Azure Key Vault in your ARM template deployment
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Andreas Baumgarten