Consume an external Rest webservice in C4C

Hello Experts!

I need to consume an external web service into my custom BO, to test the connection i used a public API https://reqres.in/api/users;

1- I created an external web service using the API https://reqres.in/api/users;

2- I Created a web service scénario

3- I craeted a communicationa arrangement

4- i created an after modify script and i added this script

capture.png

i dont know what to put exactly in the parameters . in my custom BO i have TWO fields:

captureed.png

the requirement is to get the id client from the custom bo and serch in the Api and get the email that correspand the id and put it in the field in C4C.

Urgent!

Thank you,

Sarah,