AWS MSK( Managed Streaming Kafka) : enabling IAM based Client Authentication, Information needed

I am created a Kafka Cluster using Terrafrom , this is a AWS MSK Cluster. When the cluster was created no client authentication was specified.
Now i want to add IAM based authentication to the cluster. The following block is added in the terraform script for it

client_authentication {
sasl {
iam = true
scram = false

When i run the plan , it does force a replacement of the existing Cluster. However it does seem like this operation is allowed using the AWS management console ,It alows adding IAM Client Authentication to an existing MSK cluster. The question i have is
How we add IAM based client authentication on a AWS MSK kafka cluster in terraform?

The output of the plan is shown below

  • client_authentication { # forces replacement
    + sasl { # forces replacement
    + iam = true # forces replacement
    + scram = false # forces replacement

Thanks for any help .
Best Regards