Sign in with apple PEM format

I am implementing sign in with apple to a native ios mobile app, following the instructions in auth0

creating the client secret was really difficult cause there is no clear instructions in apple or auth0 docs.

I used this link to finally create a client secret:

but then I am getting this error when trying to define the social connection:
“Error!options.app_secret must be in PEM format”
after i tryied to put the ruby script output of the signed jwt token.
the token is valid after i checked it in debugger.

if i try to wrap the token with -----BEGIN PRIVATE KEY----- and -----END PRIVATE KEY----- i am able to pass the error and configure the connection but then i am getting this error when trying the connection:
“error”: “server_error”,
“error_description”: “Failed to derive a client_secret from the configured Client Secret Signing Key.”

i have custom domain defined in my auth0 account.
the signin with apple does work for other tenants we have that are not production, but here adding the complexity of the secret key is an issue.

how do I convert from a signed jwt token to pem format?

please let me know what is missing in the puzzle…