Can't connect pppoe/dsl

I have username and password given from ISP. I have successfully connected pppoe in windows. They give me onu and I can't connect default gateway which is below the device onu. I have connected once In windows. I have created pppoe connection but can't connect. I have removed ethernet accidentally how to get it back.

I have tried all commands but still can't connect to internet.

Is this a duplicate of this thread?

It does not help anyone if you start a new thread for the same problem.

Yes. But I need answer please. Where is the problem?

@coderhasib ,
Certainly, we can relate to how frustrating an issue is and in trying to solve it.

Please allow for your existing thread to seek solutions from knowledgeable members.
Due to this being a duplicate, this thread is closed.
The existing, current and active thread that is troubleshooting this issue remains open in hopes of helping you.