How to access the local network from the outside, with a gray ip?

Question

Network administration

There is a router with the address 192.168.0.1 and a gray ip 10.**.**.**
the router is connected to a router that seems to have 192.168.0.0 or 192.168.1.1, I don’t have access to it, it was just installed by the provider, and it does not have a web interface available.
from the router comes a local network in which there are devices that need to be accessed.
So far, the application (bot) is hosted from a PC, and accesses the direct local address 192.168.0.**
If I deploy this application, how can I access the local network through a router (the computer is not always turned on)?
Google, I stumbled upon the vpnki service, but I still couldn’t ping it from the router, and vice versa, although I already tried all the methods there, and it seems to work. I also tried the no-ip DDNS service, but nothing connected here either, all ports were closed, and forwarding did not work (or I did something wrong)
Someone, please explain in detail how you can configure a router (VPN, DDNS, etc. .d.) so that I can access my local devices from the Internet?
I also heard about the Hamachi option, but this can only be done with a working PC, in theory, it can be done ...

Answer 1

In the absence of access to the inside, you need to initiate a connection from the inside to something that is accessible from the outside.
This can be, for example, the cheapest VPS, to which a router or computer from the local network will raise a VPN connection.