Access USB modem through 2 routers

this is my setup
Peplink -ethernet- Gli - USB - Huawei modem
Gli LAN port is connected to Peplink WAN port

address is for peplink
address is for gli
address is for USB modem

I cannot access the USB modem interface through the peplink wifi. I think the ports are blocked. How do I open the ports to is accessible?

Can you access via peplink wifi?

yes I can, I just can’t access the USB modem unless I connect to the gli directly

You can connect to peplink wifi and track it with the command “traceroute”

this is not command in windows
I use ping and get reply
I use ping and it times out

I use tracert and get 1 hop
I use tracert and get my VPN IP Address, which then goes through 2 more IP Addresses
I use ping on those 2 IP address and each is 1 TTL less than the previous, the times out, both are on the cloud provider