Generate Graphic Wallpaper with Midjourney, GPT-4o-mini and Canvas APIs

Who is the template for? This workflow is specifically designed for content creators and social media professionals, enabling Instagram and X (Twitter) influencers to produce highly artistic visual posts, empowering marketing teams to quickly generate event promotional graphics, assisting blog authors in creating featured images and illustrations, and helping knowledge-based creators transform key insights into easily shareable card visuals. Set up Instructions Fill in your API key from PiAPI. Fill in Basic Params Node following the sticky note guidelines. Set up a design template in Canvas Switchboard. Make a simple template in Switchboard. Click Crul and get the API code to fill in JSON of

Help me set up the n8n workflow "Generate Graphic Wallpaper with Midjourney, GPT-4o-mini and Canvas APIs" (https://n8n.io/workflows/3627). It uses: HTTP Request, Code. Import the template JSON into my n8n instance, list every credential I need to create, and walk me through testing it.