TalkingSheet works out of the box with a shared default model. If you'd rather use your own account, turn on Use my own API keyin the add-on's Settings tab and pick a provider — Anthropic, OpenAI, Google Gemini, DeepSeek, or OpenRouter — along with which of that provider's models to use.
Your key is sent along with each request and used only for that request — TalkingSheet never stores it.