Options for gaining access from the outside to the ip camera from the Internet?

Question

CCTV

There is an ip camera behind nat, there is a synology server on the same network, there is a vps server on the Internet
I would like to get access to the ip camera
At the moment I have no idea what to look for

Answer 1

It turned out that the Chinese had already set everything up
The camera is connected to the registrar, which works via goolink
And when registering on the goolink.org website, the camera can be viewed through the application of the same name on the phone, indicating the registrar's id as the identifier