What Session Token Path to use?

[AlxGlx]

I’m struggling with the requirement to have a Session Token Path.
The response from the token provider is in the form:

{
"status": 200,
"body": "[ACCESSKEY]",
"headers": {
…
}
}

As the access token is directly in the body with no identifier, what Path do I use?
I have tried *, {}, [] and all seem to result in a “KeyError”. Any help would be appreciated.