So, I solved this problem by add more parameter (verify=False at "requests,post" method) , after that error disappeared. However, I did not found any event log in my Splunk.
I have been searched the solution of this problem for 2 weeks, and cannot found any solution. So, please let me know,
can you collect and forward event log from Symantec cloud to your Splunk ? and
Could you please to solve this problem for me ?