Update lookup table values through Rest api

I am trying to create new entry in lookup table using Rest but getting an error.

ERROR : An unexpected 'PrimitiveValue' node was found when reading from the JSON reader. A 'StartObject' node was expected.
clientRequestId: af31b745-2214-4635-9a45-0fa1311e7d2c
serviceRequestId: aea3c29f-30ba-b000-fc46-67eccb973d3b

Using Post message : 

URI:

_api/ProjectServer/LookupTables('00008e67-65a3-4898-baaa-d82d995bbb02')/Entries/Add

Body 

{'parameters':{

'Value':'110',
'Description':'Added from Flow',
'SortIndex':'7',
'ParentId':'dd67bf95-85a3-eb11-bfa0-00155dc0a600'
}}
Using following References https://docs.microsoft.com/en-us/previous-versions/office/project-javascript-api/jj668218(v=office.15)

https://docs.microsoft.com/en-us/previous-versions/office/project-javascript-api/jj668483(v=office.15)