I am writing code to login into router and grab some settings. My code,that I wrote for HTML login does not work with the router login.
I have included the image. What is it ? Can I have code in c#, python or C to login into it ?

I am writing code to login into router and grab some settings. My code,that I wrote for HTML login does not work with the router login.
I have included the image. What is it ? Can I have code in c#, python or C to login into it ?

It's Basic access authentication. And yes, you can use whatever language you are comfortable with as long as you can specify custom HTTP headers for the request.
As Jifri said, it's Basic access authentication. You can log into it by sending the username and password as part of the URL you request:
http://username:password@url.com
See discussion here too: Username and password in https url