Excel VBA OpenRouter Integration

I need a compact, well-commented VBA routine that will let me type a prompt in one cell and watch OpenRouter’s plain-text reply appear in another. I’m working in Excel 2019, so the code must run smoothly there without any external add-ins... (Budget: $30 - $250 AUD, Jobs: API Development, API Integration, API Testing, Excel, Excel Macros, Excel VBA, JavaScript, JSON, Visual Basic, Visual Basic for Apps)