Why does my web application ask for credentials

i have a web application written in c#, and for some reason it always asks me for credentials (of the user logged to the computer). in the file Web.config there is a tag:

<authentication mode="Windows">
</authentication>

even if I remove this, it still asks me for credentials. There is no place in my code that asks for it. Does anyone know why it happens? i use visual studio 2019