User API on Salesflorce cant create tasks

Im working with SF with 2 diffrant user profiles

  1. regular user
  2. API user integratin ( no UI only API calles)

I have a process that create a TASK in SF due to some rules

the first user is managing to execute the process perfectly
but with the 2nd one im getting this error while tring to create a task “Call”

“Activity Insert Record - Task ended with error: Error Code: [NOT_FOUND] Message: The requested resource does not exist”

I checked the permission set of the user API it look ok

the user API runs a different process that update objects and it works fine
any suggestions?