Create an environment variable called OPENAI_API_KEY with the API key
Create a file with name .openai under user profile directory with the API key
Set API key in options, Tools->Options->Comment2GPT->General->OpenAI
Pricing: This extension is free to use, but you may need to pay for OpenAI services https://openai.com/pricing
Bug/error report & suggestions: Either use e-mail or Q&A here
Notice: This extension may collect telemetry data about your use of the software for error tracking and usage metrics. Data is anonymous and telemetry can be disabled in the options if you have privacy concerns.