[Feature Request] Use NOA Credits instead of private API keys

Hi, 
would it be possible to authenticate via the assistant to use the monthly credits instead of using private API keys in .env

i.e., add an option to use the credits in 'https://api.brilliant.xyz/noa/user', similar to the Noa APP, directly from .env file or ask for authentication via OTP.

it only makes it easier for development since I have no experience with Flutter