Hello Experts,
I have awritten apex class in which is i have used SOQL on Big Object. 
For that I want to write test class but I am not able write the test data for big object.
getting error : unsupported external object operations

List<BigObjectTaskData__b> BigObjectTaskData_ListObject = new List<BigObjectTaskData__b>();
        try{
            
            
            
            BigObjectTaskData__b bObject = new BigObjectTaskData__b();
           // bObject.Id = '0015D000006AsuNQAS';
            bObject.Task_Created_Date__c = System.today();
            bObject.whatId__c = '0015D000006AsuNQAS';
            bObject.Task_Created_By__c =  'Test';
            bObject.whoId__c = '';
            bObject.RecordType__c = 'tests havsc';
            
            bObject.Task_OwnerId__c = '0015D000006AsuNQAS';
            bObject.Task_Status__c = 'test data';
            bObject.Task_Priority__c = 'test data';
            bObject.Task_Due_Date__c = System.today();
            bObject.Task_Subject__c = 'Test Data';
            bObject.Task_Comments__c = 'Test Data';
            
            bObject.Task_Call_Duration__c = 15;
            bObject.Task_Related_Record__c = 'Test Data';
            bObject.Task_Call_Regarding__c = 'Test Data';
            bObject.Task_Result__c = 'Test Data';
            bObject.Task_Reason__c = 'Test Data';
            
            bObject.Task_Last_Modified_date__c = System.today();
            bObject.Task_Last_Modified_by__c = 'test data';
            
            bObject.Task_Owner_name__c = 'Test';
            bObject.Task_parent_Name__c = 'tname';
            bObject.Task_related_to__c = 'leObj';
            
            BigObjectTaskData_ListObject.add(bObject);
//            insert BigObjectTaskData_ListObject;
            database.insertImmediate(BigObjectTaskData_ListObject);
//            Obj1.bigObjectDataList.addAll(BigObjectTaskData_ListObject);
        }
        catch(Exception e)
        {
            System.debug('Exvception : '+e);
        }

Thanks in advance.