Using Dynamic DNS in the router will resolve your issues. See the link I posted on how to set it. The Dynamic DNS servuce will update regularly with your new IP when DHCP changes it which is not very frequently.
Exactly, DNS would only work if you had a public IP address assigned to your router, but is of no use to you now since it has a private non routable address as Verizon uses the double NAT system.
Every router has to have a public IP otherwise you cannot get outbound. I am not sure what you mean by double NAT. That's almost like saying there is a NAT between the WAN and the router and another between the LAN and the WAN.
I have a Verizon router for a secondary backup in case my gig fiber fails and use Dynamic DNS for both since I run OpenVPN.
Never had issues routing to it externally with a public IP that was assigned dynamically.
Sorry if I am missing the point.
All routers do not need or have a public IP address for outbound. All routers that connect directly to the Internet would need a public IP address. The 4g lte router doesn't connect directly to the Internet, it connects to a Verizon network server behind a firewall, and the server has a public ip that routes the traffic. It's basically like a private network at home, connecting to Verizon's private network connecting you to the Internet (double vs single nat).
If yours is working with your setup it's due to your VPN, which is why I mentioned that as a workaround above, as VPNs can securely tunnel trough the network firewall both ways.
OK after chatting with Verizon static IP is out if the question. I need a business account which I don't have and even if I had s business account the setup for a static IP costs $500 which I can't afford. Now the second way was using a VPN. How do I do this without a PC?
Yeah that is expensive! I've never personally used a VPN solution without a physical PC sever, but maybe someone here that has more knowledge on any other VPN connections will chime in. Alternatively, a local computer store might have more experience with alternative setups, or a company that provides VPN products like Cisco.
Seems like you found a solution.
Otherwise setting up a VPN connection direct from a modified home router is the only other way to provide network devices like security cameras a public IP address while connected to the VZW network. This has been well documented as a limitation since the release of the 4G LTE network several years ago. You can get it to work, but it often requires time and skills that are above most peoples interest levels.