Make a branded voucher or receipt with an instalment plan. Save it as a PDF, or as an image to send on WhatsApp.
Upload a CSV with one student per row. Columns: name, phone, batch, fee, discount, plan, first_due (plan is 1, 2 or 3; date as YYYY-MM-DD). Fee, payment details and notes default to what's filled in above. You get a zip with one PDF per student.