Automated PDF Invoice Processing & Approval Flow using OpenAI and Google Sheets

Who is this for? This workflow is ideal for: Finance teams that need to process incoming invoices faster with minimal errors Small to mid-sized businesses that want to automate invoice intake, review, and storage Operations managers who require approval workflows and centralized record-keeping What problem is this workflow solving? Manually processing invoices is time-consuming, error-prone, and often lacks structure. This workflow solves those challenges by: Automating the intake of invoices from multiple sources (email, Google Drive, web form) Extracting invoice data using AI, eliminating manual data entry Implementing an email-based approval system to add human oversight Automatically sto

Help me set up the n8n workflow "Automated PDF Invoice Processing & Approval Flow using OpenAI and Google Sheets" (https://n8n.io/workflows/4452). It uses: Google Sheets, Google Drive, Gmail, AI Agent, OpenAI Chat Model, Structured Output Parser. Import the template JSON into my n8n instance, list every credential I need to create, and walk me through testing it.