学校費用支払いのフローチャート

A clean, professional flowchart diagram showing a school fee payment system. The flow starts with Parent/Student Portal, then School Software, then Hubtel Payment Gateway, then Mobile Money Wallet (MTN/Telecel/AT), then Parent enters PIN to approve payment. A webhook callback goes from Hubtel back to School Software. Use clear boxes with arrows and labels. White background, minimal style.