Localhost login pops-up at the top of the screen

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In VSC I have open 2 files, a HTML and a CSS. Everytime I type in the css file at the top of the screen a text line opens asking to enter a password.
[localhost]: enter your password (press 'Enter' to confirmor 'Escape' to cancel)

What is this and how to get rid of it?

Thanks in advance for your cooperation

What I have tried:

I looked into the settings, but I am a beginner in coding. I not find what to do.