@greyteapot I'm sorry. Blame on me. I thought that community.nodebb.org ist just an alias for your own instance.
Authentication is handled either via HTTP Bearer Token or JSON Web Token, as generated/specified in the Write API.
https://github.com/NodeBB/nodebb-plugin-write-api#authentication
So I think there is no way for you to read user specific data on community.nodebb.org.
But for your own instance you would use the generated bearer token.