Unable to read source lists in Ubuntu 18.04

Question

In my previous question I got an answer N0bert and I believe it caused the problem apparent in the picture and post title.

"malformed line 2 in source list"

Does anyone know how to resolve this?

Regards

Answer 1

The red warning dot disappeared and I can run updates and install things since I ran the code properly, the same code that caused the problem when I input it wrong.