Advice on Configuring a 4g Router to a DVR

Hi

I have purchased a 4g wireless router and I am looking to access a CCTV system/DVR from my Android phone. I fitted an EE static IP SIM in the router and have configured the machine so I now have internet access. I would be grateful if someone could advise me on the setting for the DVR and router to enable me to access them remotely . I would also be very grateful if someone could recommend an APP for my phone. I have Eagle eyes on a system that I can access from my WIFI at home which I managed to configure successfully.

Thanks in advance.

Kind regards

Mike