If the camera doesn't have a reset button (under the MicroSD card cover), you need to generate a reset file using the SADP software. You can then send the reset file to your supplier or direct to Hikvision and they will return another file that can be uploaded to complete the reset.
This article explains the process
https://connectec.uk/how-to-reset-the-password-of-a-hikvision-or-hilook-device
