Running EPM Integration gives me nullPointerException

Summary:

Running a Data Management Pull of data using Groovy "befExtract" from windows to the EPM using Integration.

Content (required):

we are trying to connect to a third party cloud solution through REST API to integrate automatically through EPM Agent API Connection then get back JSON data using JsonSlurper then write it to a DAT file in order to extract the job into the EPM. we even tried to load data from static JSON and still not working

Following the Oracle Documentation, we found that it's Basically applicable using Before Extract script.

 I followed multiple scenarios with some Online Topics but with no hope. Everything is exactly the same. the Scripts exists in “EPMAgent/EPMData/scripts”