Cannot access https://dev.azure.com/<myOrg> Using TFS extended client version 15 - azure-devops

Question

We are migrating some code that used to run against an on premise TFS server but now needs to run against Azure DevOps (previously Team Services). The credentials I'm using have been validated to successfully authenticate to our DevOps organization instance, but running the following code after referencing the
Microsoft.TeamFoundationServer.ExtendedClient
NuGet package always results in TF30063: You are not authorized to access https://dev.azure.com/<myOrg> The code is posted below for authenticating via non-interactive authentication. Do I need to use a different authentication mechanism or different credentials type to get this working?
System.Net.NetworkCredential networkCredential = new System.Net.NetworkCredential(_userName, DecryptedPassword, _domain);
try
{
// Create TeamFoundationServer object
_teamFoundationCollection = new TfsTeamProjectCollection(_serverUrl, networkCredential);
_teamFoundationCollection.Authenticate();
}
catch (Exception ex)
{
// Not authorized
throw new TeamFoundationServerException(ex.Message, ex.InnerException)
}

Answer 1

Since you want to use .Net Client Libraries, you could refer to the following link:
https://learn.microsoft.com/en-us/azure/devops/integrate/concepts/dotnet-client-libraries?view=azure-devops
Patterns for use:
using Microsoft.VisualStudio.Services.Common;
using Microsoft.VisualStudio.Services.Client;
using Microsoft.TeamFoundation.SourceControl.WebApi;
using Microsoft.VisualStudio.Services.WebApi;
const String c_collectionUri = "https://dev.azure.com/fabrikam";
const String c_projectName = "MyGreatProject";
const String c_repoName = "MyRepo";
// Interactively ask the user for credentials, caching them so the user isn't constantly prompted
VssCredentials creds = new VssClientCredentials();
creds.Storage = new VssClientCredentialStorage();
// Connect to Azure DevOps Services
VssConnection connection = new VssConnection(new Uri(c_collectionUri), creds);
// Get a GitHttpClient to talk to the Git endpoints
GitHttpClient gitClient = connection.GetClient<GitHttpClient>();
// Get data about a specific repository
var repo = gitClient.GetRepositoryAsync(c_projectName, c_repoName).Result;