Function create_token_with 

pub fn create_token_with(
    scope: &str,
    entropy: &dyn Entropy,
) -> Result<String, Error>

An image-create idempotency token, unique per attempt, with its nonce drawn from entropy.

scope is a label only — a readability aid for whoever reads CloudTrail, folded in beside the nonce. It cannot become the token, and there is no parameter that can: see the module docs for the fifteen-hour wedge that closure exists to prevent (docs/PLATFORM.md, “clientToken is a permanent idempotency key”). An unavailable source is an error. microvms_core::control::token::create_token is this over the OS pool, under the name it had.