Get Refresh_Token from auto refresh collection based auth

I’m using the Authorization-Tab from a collection to obtain my tokens from keycloak.
I gave the token a name “acme_Token”.
All child-requests are using inherit auth from parent. All is working well.
But now I came to the logout-request. There the clientId and the refresh_token are needed to logout the current user.
The clientId is no problem because it is a collection-variable, but I can’t figure out how to get the refresh_token from the parent (collection-node).
I tried something as:

var jsonData = pm.response.json();
pm.environment.set("refresh_token", jsonData.refresh_token);

On the Tests-Tab of the collection.

I also tried to read the named “acme_Token”, but I can’t get it.

How can I use the actual refresh_token (automatic refresh) of the collection-node in a child-request?