The following are available extensions to extend WooCommerce PDF Vouchers functionality.
WooCommerce PDF vouchers - Import Voucher Codes add-on allows you to import and validate the voucher codes in bulk.
Purchase ExtensionWooCommerce PDF vouchers - Reverse Redemption add-on allows you to undo already redeemed voucher codes.
Purchase ExtensionWooCommerce PDF vouchers - OTP Verification add-on allows you to send OTP (Once Time Passcode) either on email or mobile on voucher code redemption.
Purchase Extension