Anyone here know how do I "extract" my "own personal" username & password from my TM stock router, Netis DL4480V, so that I could set up my new router?

My router was set up by TM technician many years ago. The technician never gave me my "own personal" username and password.

I tried the HTML method that mentioned in previous page but the username and password are "pppoe@ccs" & "3487_TmPPPoE", which I believe are default username and password.

I tried "backup" method but the backup .xml file is encrypted.

What I see on the router's WAN Set Up is this: