How can I get change history data of work items.

My scenario is :

I want change history data of a work items which are modified in between 1 apr 2021 to 7 apr 2021 and I tried some REST API to fetch details but when I got response then I get only default attributes values I am not get customAttributes values even I change custom attributes as well, so my question is

1. can I get list of work items which modified in between 1 apr 2021 to 7 apr 2021 with REST API.

2. How can I get custom attribute values in response.

I tried following REST API to get change history of work items.

<workitem Version="1.0.0" rel="next" href="https://localhost:9443/ccm/rpt/repository/workitem?id=_zXUqwJhHEeuAZLCPfd2uXg&fields=workitem%2FworkItem%5BprojectArea%2Fname%3D%22Tata%20Sky%20Business%20IT%20Requirement%20Management%22%20and%20modified%20%3E%202021-04-07T10%3A10%3A53.000-0500%5D%2F&size=100&pos=100"> <o:p> </o:p>

<workItem> <o:p> </o:p>

<projectArea/> <o:p> </o:p>

<modified>2021-04-08T14:22:46.275+0530</modified> <o:p> </o:p>

<uniqueId>95a6330f4bdbee5b6072de1f0a558aaf</uniqueId> <o:p> </o:p>

<reportableUrl>https://localhost:9443/ccm/rpt/repository/workitem/workItem/id/71</reportableUrl> <o:p> </o:p>

<itemType>com.ibm.team.workitem.WorkItem</itemType> <o:p> </o:p>

<stateId>_yex5MJhHEeuAZLCPfd2uXg</stateId> <o:p> </o:p>

<itemId>_slAN0JdUEeuK1oCj6MgfUA</itemId> <o:p> </o:p>

<contextId>_Tb3F8JbiEeuuT7fgxyJ2gQ</contextId> <o:p> </o:p>

<predecessor>_ycsOgJhHEeuAZLCPfd2uXg</predecessor> <o:p> </o:p>

<id>71</id> <o:p> </o:p>

<resolutionDate/> <o:p> </o:p>

<summary>FPM - test of 7 apr ereyherheyherty4y4y4yetyhtey4tyt4y35</summary> <o:p> </o:p>

<creationDate>2021-04-07T09:22:59.595+0530</creationDate> <o:p> </o:p>

<dueDate/> <o:p> </o:p>

<description/> <o:p> </o:p>

<workflowSurrogate/> <o:p> </o:p>

<tags/> <o:p> </o:p>

<duration>-1</duration> <o:p> </o:p>

<timeSpent>-1</timeSpent> <o:p> </o:p>

<correctedEstimate>-1</correctedEstimate> <o:p> </o:p>

<modifiedBy/> <o:p> </o:p>

<creator/> <o:p> </o:p>

<owner/> <o:p> </o:p>

<category/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

<customAttributes/> <o:p> </o:p>

In above response I got change history of work item id 71 but I got only default attribute values not get customAttribute values so anyone can tell me how should I get custom attributes. 

Thanks in advance.