Keep a sequence and an independent archive
The first PDF download assigns a number by locale, document type and year. Separate browsers have independent counters. Account for any other invoicing tools before using this sequence.
Keep your PDFs and a JSON backup elsewhere. Local history keeps 50 documents and is not a legal archiving service. Importing a backup replaces the current local data after confirmation.
Example to adapt
A reference such as QUO-2026-0001 identifies the quote in this browser. Keep the exported PDF and JSON backup separately. 2 devices have independent counters; check the numbering before issuing an invoice.