How to use Call REST response in Javascript Action Chain?

Summary:

can someone show it here how we can consume REST response,

I'm currently using the Call REST in action chain, and I need to get the a value of the specific field in the response.

Example is the REST to get_resources, there is a field in the response that i wanted to consume
let say we have custom fields inside the resource object

Custom_Field1 and Custom_Field2

can i get it from the above response? how?

something like

const Field 1 = response2.body.items.Custom_Field1

also notice that the $user.userId is not returning any value

in which i tried to use the getuserId() as mentioned below, however it return different value/number