extrememike

This is my first installation ever. I bought a Hikvision DS-7600 series NVR to use an Acti E73 I bought a few years ago. The camera is a PoE and it says is ONVIF compliant. I followed the instructions and added the camera manually but it won’t connect to the NVR I connected the camera directly to the network using an PoE switch and I’was able to find its IP address using a PC. However I cannot access it through the web browser since I don’t have the login credentials. Already tried defaults. Most likely changed these and don’t remember? Anyway to recover them? In the Hik NVR menu I have included the IP address and selected Acti for the protocol. Changed the port number to whatever number I set up for port forwarding in my router. There is a field for the camera username and password and I have left this blank. Again not sure if this is part of the problem?? Thanks in advance.