Handling corrections for zero-rated tax invoices during inventory storage, failed exports, or quarter-end closing

I am a practitioner in the export trade industry. There are cases where exported goods cannot be shipped in the same month they are purchased and must be kept in inventory for a certain period. In such cases, we issue a zero-rated tax invoice at the time of purchase and provide a purchase confirmation to the supplier. 1. I am wondering if it is legally permissible to issue a standard tax invoice at the time of purchase and then correct it to a zero-rated tax invoice at the time of export (in a subsequent month rather than the current month). 2. Since there may be cases where export becomes impossible due to local circumstances in the destination country, I am looking for a lawful way to handle this. If export becomes impossible and returning the goods to the domestic supplier is also not an option, resulting in the goods being scrapped, I would like to know if the existing zero-rated tax invoice must be converted back to a standard tax invoice. 3. In cases where the quarter-end has passed and it is impossible to correct the tax invoice, I would appreciate your advice on how to handle the situation.