Router Won't Connect To Internet

I wanted to set up my two routers to mask my IP address as I work remote globally, however, my router is wired to my internet service providers modem and it still won’t connect! What can I do

Can you ping and nslookup domains?

I’m not sure how to check, sorry I’m not tech savy. But basically I have it hooked up to my ISP’s router with the Ethernet, and I’m using your AX 1800 and AX 1300 to work remote overseas and mask my location. But the entire duration of me setting it up, it kept saying I wasn’t connected to the internet.

Looks like that DNS server has DDoS attacked? Can you change DNS address?