Setting up a rebranded Hikvision NVR

[DEWBUNKER]

Hi,

I am a bit lost and would really apprecaite some help.

The old owners left a NVR which is a rebranded Hikvision. I can see all the cameras and its records. I would like to be able to access the cameras when out of the house. Here are some thoughts/bits of information:

• I have a TP-Link Wifi 6 access point and an Archer C9 which connects to my modem. the NVR has an Ethernet cable to the Archer C9.
• I have a static IP for my NVR and can go to this IP and log into it when I am on the local network
• I created a No-IP account and entered all the information in the DDNS tab of the NVR but but says it cant connect. I've gone through a couple of tutorials and it seems i've put in everyhting correctly
• I have a question, do I need the ports on my modem open for the DDNS to connect? I presume so. I went into my C9 and created virtual servers for the all ports mentioned in the NVR and used the NVR's IP. Everything seems to be the same. I have reset it a few times.
• I have tried to check the ports online and they always say closed, I can't work out why they are not open.

Can anyone please point me in the right direction on what to do next?

Thanks!