Environment variable not found in kotlin notebook

Need:  Read variables from system env

System: Intellij IDEA (Ultimate), Windows 11

Context: Writing kotlin code in a kotlin notebook and reading an env variable 

Problem:

System.getenv("USERNAME") ?: error("USERNAME not found")
System.getenv("AWS_DEFAULT_REGION") ?: error("AWS_DEFAULT_REGION not found")

USERNAME is found in system variables
AWS_DEFAULT_REGION is not found! Although it is set in “User environment variables” by hand.

The variable should be found. Best case scenario automatically by 

DynamoDbClient.builder()
.credentialsProvider {
  EnvironmentVariableCredentialsProvider.create().resolveCredentials()
}

Running the ipynb file in IDEA as “Run in IDE Process”, the variables are not found although i see them in notebook settings > JVM and Build > Environment variables.
Also when i set them in console, IDEA does not show the in “Include system environment variables”. Not after restart or any other way..

Can someone confirm this behavior or give a hint what i am doing wrong? Why is IDEA not listing the system variables although i set them and see them in the console or even in idea itself… 

(i am new to notebooks and windows :))

thanks