How do I get the free Google Gemini API key?

In BookyAI open Settings, stay on "AI engines", click "Gemini", then click "Get your free Gemini key: step by step" (from version 1.9.17). The steps are: 1) Click "Open Google AI Studio" in the instructions, or go to aistudio.google.com/apikey, and sign in with your Google account (the one you use for Gmail works). 2) On your first visit, accept Google's terms. 3) Press "Create API key"; if Google asks for a project, choose to create the key in a new project. 4) Press the copy icon next to the key. Do not retype it by hand: it is long and every character counts. 5) Back in BookyAI, click in the key field, paste, press Save, then press Test. A green "Key works" line and the "Connected" badge mean you are ready. The key is free and needs no card. A Gemini key usually starts with "AIza".