A: Hi, UPDF does not currently support the direct use of USB Tokens. However, if your certificate can be exported in pfx format, you can use it to add a digital signature within UPDF. Thank you for your feedback. We will continue improving our product in the future to make it work better for you. If you have any other questions, please feel free to contact our customer support team at [email protected] for further assistance. Thank you again for your support and understanding.