GSTR-1 Export Invoice Query - Partial Payment Received

I need guidance on a specific export invoice scenario for GSTR-1 filing:

Situation:

• Original Invoice: $907 USD (dated June 26, 2025) - Export under LUT to US company
• Payment Received: Only $500 USD (received July 10, 2025)
• Shortfall: $407 USD - Client company facing financial issues, uncertain if remaining amount will be received

My Actions:

1. Filed GSTR-1 for June 2025 with ₹42,876 (converted $500 at June 26 exchange rate)
2. Reported this as the actual export value in Table 6A
3. Did not include the unpaid $407 portion

Questions:

1. Was this approach correct? Should I report the full original invoice value ($907) or only the amount actually received/realizable ($500)?
2. If I receive the remaining $407 later (say in August 2025), how should I handle it in GSTR-1? Create supplementary invoice for that month?
3. What if the $407 becomes a bad debt? Any specific treatment required for export bad debts under GST?

Additional Context:

• This is under LUT (no GST liability)
• Both original invoice and payment are properly documented
• Client indicated financial stress but no formal write-off yet

As 11 was last date so i filled with this info do le me know if i should upate my gstr1 ?