To save the customised voucher format, you need to follow the below steps:
Step 1: Go to Transactions, then select Voucher, then click on Modify, then put the voucher number that you want to save, and click on OK or F2 to save the transaction.
Step 2: After loading the voucher, you need to click on the print option. After clicking on the print option, you will find the option to select the sale invoice.
Step 3: And then you have to select the format for printing. In that option, you need to select your customised voucher format.