Error with GET_REQUESTS operation

I am using ManageEngine ServiceDesk Plus version 8.1.0 build 8123 and I am trying to connect via REST API to get a list of all requests and their details. I am using the following parameters:

URL: http://<servername>/sdpapi/request/

Method: POST

OPERATION_NAME: GET_REQUESTS

TECHNICIAN_KEY: <key>

INPUT_DATA: 

1. <Details>
2. <parameter>
3. <name>from</name>
4. <value>0</value>
5. </parameter>
6. <parameter>
7. <name>limit</name>
8. <value>25</value>
9. </parameter>
10. <parameter>
11. <name>filterby</name>
12. <value>All_Requests</value>
13. </parameter>
14. </Details>

But I am getting this response:

1. <operation name="GET_REQUESTS">
2. <result>
3. <status>Failed</status>
4. <message>Error when performing - GET_REQUESTS - java.lang.Long</message>
5. </result>
6. </operation>

Also, I have already tried the solution as seen in this forum: https://forums.manageengine.com/topic/how-to-access-all-the-requests-in-service-desk-plus-using-rest-api, but it still wouldn’t work and it returns the same message above.

Am I doing something incorrectly?