sam invoke local - should AWS_SESSION_TOKEN be an empty string?

[leepowellnbs]

Obviously if I run my lambda within AWS the AWS_SESSION_TOKEN is populated and can be used for things such as accessing secrets. However when I run sam invoke local the token is just an empty string and I'm unable to use it for any of these services.

Is this expected behaviour? Am I meant to create this session token myself? I'm using the Node18 runtime.