Unable to pick aws region from properties and env for aws MKS

[lalit2001]

i was trying to set

aws.accessKeyId = ${AWS_ACCESS_KEY_ID}
aws.secretAccessKey = ${AWS_SECRET_ACCESS_KEY}
aws.region=eu-west-2

access key and secret access key is getting picked up but when it comes to aws.region its not getting picked up from end but if I set it on was profile its picks it up from there here is my Kafka props

kafka.bootstrap.servers = ${KAFKA_SERVER_URL:localhost:9092}
kafka.security.protocol=SASL_SSL
kafka.sasl.mechanism=OAUTHBEARER
kafka.sasl.jaas.config=org.apache.kafka.common.security.oauthbearer.OAuthBearerLoginModule required;
kafka.sasl.login.callback.handler.class=co.uk.altiorsolutions.insightsservice.configs.CustomIAMOAuthBearerLoginCallbackHandler

[lalit2001]

getting AWS region could not be resolved.: java.io.IOException: AWS region could not be resolved.
at software.amazon.msk.auth.iam.IAMOAuthBearerLoginCallbackHandler.getCurrentRegion(IAMOAuthBearerLoginCallbackHandler.java:190)
at software.amazon.msk.auth.iam.IAMOAuthBearerLoginCallbackHandler.handleCallback(IAMOAuthBearerLoginCallbackHandler.java:142)
at software.amazon.msk.auth.iam.IAMOAuthBearerLoginCallbackHandler.handle(IAMOAuthBearerLoginCallbackHandler.java:123)