iOS: BOX Enterprise APP - JWT creation issue

Hi Team,

As per the below documentation, I have created the enterprise app on box dev portal and trying to do Authentication using JWT.

Documentation:  https://docs.box.com/docs/app-auth

Using JWT Objective-C lib:  https://github.com/yourkarma/JWT  ,

created the JWT but when I use with curl command got error as

Error:

{"error":"invalid_grant","error_description":"Algorithm not allowed"} 

// curl command - (run command by adding app client key and client secret)

-d 'grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer&client_id=YOUR_CLIENT_ID&client_secret=YOUR_CLIENT_SECRET&assertion=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJqdGkiOiJKVlVQWFdkRXJMbk51NHhLIiwiZXhwIjoxNDkwNzk3NDUwLCJpc3MiOiJrQ2xpZW50SUQiLCJib3hfc3ViX3R5cGUiOiJ1c2VyIiwic3ViIjoiNTQiLCJhdWQiOiJodHRwczpcL1wvYXBpLmJveC5jb21cL29hdXRoMlwvdG9rZW4ifQ.VZwW_8EHm-Ox8k2TC4XjeF_GWtXTi2MnAvVHGCgNU30' \

-X POST

Please guide to create the JWT token for enterprise app?

Thanks, 

Pravin