Get regarding field value from a task in Dynamic CRM

Hi all,

I am a beginner to CRM dynamics.

I'm trying to get Regarding field in a task by API (Retrieve related entities for an entity by expanding navigation properties)

/api/data/v8.0/tasks?$select=*&$filter=statecode eq 0 and Microsoft.Dynamics.CRM.EqualUserId(PropertyName='ownerid')&$orderby=scheduledend desc&$top=10&$expand=_regardingobjectid_value($select=name)

I got a value from "_regardingobjectid_value" value when receiving a task but it said Bad Request for my request.

Do you have idea how to fix this?

Thanks,

Hon