The camera in your eBay link is only designed to feed a signal to a video recorder, not into the internet for access via a smartphone.
Any camera that sends its output to a smartphone needs to initially get it to a router, so that it can become accessible remotely via a smartphone. So if there's no wi-fi router in your father's home, together with an internet subscription associated with it, you're wasting your time by trying to do the impossible.
Assuming that there's an internet connection in your father's home, this is what you need:
https://ring.com/products/mini-indoor-security-camera
[Note 1: You'll need a power adapter for each camera. Note 2: If you only want to be able to see what's going on in real time, you don't need to subscribe to 'Ring Protect'. However you will need Ring Protect if you require recording facilities].