How do I modify the auto-generated invoice number for the new financial year? 

To modify/update the auto-generated invoice number for the new financial year:

• Go to the Invoices module on the left sidebar.
• Click the + New button on the top right corner of the page to create a new invoice.
• Go to the Invoice# field and click the Gear icon next to it.
• Edit the prefix of the invoice number based on the new financial year’s sequence. For example, if you’ve been using INV23-xxxx, you can change it to INV24-xxxx.
• Edit the Next Number field if you would also like the invoice number to start from one for the new financial year.
• Click Save.

Now, the invoice number will be auto-generated with the new prefix and next number for every new invoice.