Hello Jyotsna,
Yes, I was able to test it and it works as expected with that platform version. What I also found out is that the input parameter Client.PrivateKey in the GetToken action, needs to be set to a multiline string, and it doesn't support "\n" characters.
So, if you're inputting your private key as a single line string like:
"-----BEGIN PRIVATE KEY-----\nMIIEvQ....\n-----END PRIVATE KEY-----\n"
That will generate the error message "Object reference not set to an instance of an object. "
In order to set the private key correctly, you'll need to set as a multiline code, by replacing the "\n" with actual new lines, like:
"-----BEGIN PRIVATE KEY-----
MIIEvQ....
-----END PRIVATE KEY-----"
Then it should work.
If you can't overcome the problem with this information, I ask you to provide a sample app with the input valures (test values) you're using to call the GetToken.
Thanks
Cheers