QR-Based Chemical Inventory Automation

I need a lightweight system that lets my supervisors raise chemical indents by simply scanning a QR code on each item, while the stock ledger in a central spreadsheet adjusts itself and notifies us if anything drops below the reorder level.

Current flow I want to replicate
• Supervisor scans item → quantity auto-captured in an online “Indent” sheet
• Store staff see that entry, issue the material, and log the movement with one more scan
• By the next morning the office team reviews and formally approves or queries the issue, again inside the same file
• All of these touches must write to a time-stamped log so audit trails are intact

Technology
I am open to Google Sheets with Apps Script or Excel + Power Automate—whichever gives us the lower running cost. Please highlight any licence fees you foresee.

Key requirements
• Dynamic QR codes generated on the fly for new SKUs
• Both WhatsApp and email alerts when stock reaches the minimum level (I’m fine with Interakt, Gupshup or another economical gateway)
• Single, always-up-to-date stock sheet plus a separate immutable transaction log
• No manual consolidation at day-end; everything has to reconcile automatically

Deliverables
1. Fully functioning prototype connected to either Sheets or Excel, including the automation scripts/flows
2. Integration with the chosen WhatsApp API and an email relay
3. Clear setup guide so my team can redeploy or extend it without extra licences
4. One-hour hand-off session to walk us through the code and settings

Acceptance will be based on a live demo where I create a new item, print its QR, issue it, and see the ledger update along with both WhatsApp and email alerts.

Cost matters, so please keep solutions lean and reusable.