If you want to integrate the Web App Sign In & Sign Out with Azure AD, we can using the use the OWIN authentication pipeline with code below:
public void ConfigureAuth(IAppBuilder app)
{
app.SetDefaultSignInAsAuthenticationType(CookieAuthenticationDefaults.AuthenticationType);
app.UseCookieAuthentication(new CookieAuthenticationOptions());
app.UseOpenIdConnectAuthentication(
new OpenIdConnectAuthenticationOptions
{
ClientId = clientId,
Authority = authority,
PostLogoutRedirectUri = postLogoutRedirectUri,
});
}
And we need to register the app with Azure AD to get the client Id. More detail you can refer to here.