Hi @konrad.sopala ,
The quickstart only covers configuring the callback URLs under ‘Allowed Callback URLs’ , in which case entering localhost (without the .com) works fine. No problems there.
I should mention it’s also not a problem for the ‘Allowed Logout URLs’. https://localhost:44344 works fine for that.
It appears to only be a problem for the ‘Application Login URI’, which isn’t specifically covered in the quickstart.