Apologies for not explaining the electrical details in a professional manner and maybe I should have found a forum for CCTV matters. I'm not an electrician but an elderly and pretty capable DIYer.

As I said earlier I have been using old style (coil) relays specifically the MY2NJ type and they have worked with the 5 cameras I have.
I use a 240v PIR sensor that sends 240v to the relay when it is activated. The relay, when activated, makes or breaks contact in the camera. This triggers the camera to start recording. Here is an extract from the manual...........
"""Trigger
This is the cause or stimulus which defines when to trigger the Network Camera. The trigger source can be external digital input devices. This option allows the Network Camera to use an external digital input device or sensor as a trigger source. Depending on your application, there are many choices with digital input devices on the market which help detect changes in temperature, vibration, sound, light,"""