How to call amount in odata via postman API

Please advise how to request money through postman API, Now I response message “Invalid parametertype used at function ‘eq’ (Position: 72)” this is error message.
Example.
URL : https://test.com/BOT_SRV/OverClaimSet?$format=json&$filter=CLAMT eq ‘15000’
CLAMT = Claim amount is name function unique
Thanks for your help.