C# Azure Key Vault authentication using a service principal secret

BasicKeyVaultAuthentication.cs

// SEE http://www.industrialcuriosity.com/2018/03/azure-key-vault-in-c-for-dummies.html FOR FULL EXPLANATION

/// <summary>
/// Gets the access token
/// The parameters will be provided automatically, you don't need to understand them
/// </summary>
/// <param name="authority"> Authority </param>
/// <param name="resource"> Resource </param>
/// <param name="scope"> scope </param>
/// <returns> token </returns>
public static async Task<string> GetAccessToken(string authority, string resource, string scope)
{
    // NOTE: for the love of god, this is just for clarity - please don't store the credentials in your code
    
    // application id from registered app
    string clientId = "c641ac7b-fb34-469d-b9e2-c7f15f8656dc";
    // any of the registered app's valid keys
    string clientSecret = "P91isDd/RrEvIgrqRRzG5359ubvfLPZIHaYM91qNSQ0=";
    
    ClientCredential clientCredential = new ClientCredential(clientId, clientSecret);

    // create context with default token caching
    AuthenticationContext context = new AuthenticationContext(authority, TokenCache.DefaultShared);
    AuthenticationResult result = await context.AcquireTokenAsync(resource, clientCredential).ConfigureAwait(false);
    return result.AccessToken;
}

/// <summary>
/// Connect, set and read a secret
/// </summary>
/// <returns> secret </returns>
private async Task<string> KeyVaultTest()
{
    string vaultBaseUrl = "https://YOUR_KEY_VAULT_NAME.vault.azure.net";
    string secretName = "KeyVaultTest";

    // Connect client
    KeyVaultClient keyclient;
    try {
        keyclient = new KeyVaultClient(
            new KeyVaultClient.AuthenticationCallback(GetAccessToken)
        );
    } catch (Exception keyVaultClientException) {
        throw new Exception("client construction: " + keyVaultClientException.Message);
    }

    // Set secret
    string secret = "My s3cr3t value!";
    try {
        SecretBundle result = await keyclient.SetSecretAsync(vaultBaseUrl, secretName, secret);
    } catch (Exception setSecretException) {
        throw new Exception("set secret: " + setSecretException.Message);
    }

    // Read secret
    try {
        string secretUrl = $"{vaultBaseUrl}/secrets/{secretName}";
        SecretBundle secretWeJustWroteTo = await keyclient.GetSecretAsync(secretUrl);
        return secretWeJustWroteTo.Value;
    } catch (Exception getSecretException) {
        throw new Exception("get secret: " + getSecretException.Message);
    }
}

Could you share a sample to call it? Thanks!!!

Could you share a sample to call it? Thanks!!!

I'm not sure I understand the question, as the contents of KeyVaultTest() is a collection of sample calls to KeyVaultClient methods. Ignoring the fact that this was written three years ago and that the interface may have evolved since I last used it, what is it you're trying to do?