I cannot sign in when I create a new Azure App Service. I have already signed in with Authenticator and it even shows my account. I am sure I have signed in correctly and I also do have an Azure account. When I sign in, it still shows me the same panel as if I wasn't signed in. I am following Microsoft official documentation. Seems like that's visual studio's issue. Thanks in advance.
You are facing transient issue in Visual Studio while signing into your Azure account. Close your visual studio instance and re-open it and try.
In your windows machine> Select Default apps and select the Default browser to Internet Explorer/Microsoft Edge as below:-
In your Visual studio > Select your account from right top > Account Settings > and make sure you have the below settings with Embedded web browser and URL set:-
In the same Account settings make sure your account is selected for Azure Service Authentication like below:-
According to this MS Q & A forum answer. If the issue persists with Embedded web browser select System web browser and sign in again with your Azure account.
Click on Sign out and Sign in again:-
Also, According to this SO thread answers on the same issue as yours:-
Close all Visual studio IDE's that are open.
Go to Local AppData and remove "IdentityService" file that is hidden.
C:\Users\username\AppData\Local\.IdentityService
C:\Users\username\AppData\Local\Temp
Try signing in with a different account that has permissions assigned on your Azure subscription and sign in again with your account.
Make sure the Account you are signing in with has atleast contributor role assigned at your Azure subscription level for the user to access Azure subscription and its App service resources like below:-
You can check your account access like below as I have Owner role assigned make sure you have atleast Contributor role assigned to your Azure account:-
Apart from this, If you get a pop up to Re-enter your credentials below your account, Make sure you re-enter your credentials and unselect or select the correct directory, If you unselect another directory by default the default directory will be selected like below:-
Additional Reference:-