Error with privatekey

[huxley-goh]

Hello,
I wish to have more clarity on the below error message. I have set the environment variable "FIREBLOCKS_API_PRIVATE_KEY_PATH" to contain the PEM encoding in a literal string converted by following this guide https://gist.github.com/bitroniq/841430aee4d58d37f56d93ea71a8d99c

{'message': 'secretOrPrivateKey must be an asymmetric key when using RS256', 'code': -32603}