How to set User Agent string in MSGraph .net SDK - user-agent

Question

I'm reading customer email accounts using the MSGraph SDK v4.27.0 in C#. It works fine but one customer insists on using allowlists for EWS access to email. That grants access to apps that supply a User Agent string but how do I include it in the MSGraph header using the SDK calls?
The code is taken from the MS example
var scopes = new[] { "User.Read","Mail.ReadWrite","Mail.ReadWrite.Shared" };
var options = new TokenCredentialOptions
{
AuthorityHost = AzureAuthorityHosts.AzurePublicCloud
};
var userName = strAccount;
var password = strPWD ;
var userNamePasswordCredential = new UsernamePasswordCredential(
userName, password, tenantId, theClientId, options);
var graphClient = new GraphServiceClient(userNamePasswordCredential, scopes);
try
{
rootFolder = await graphClient.Me.MailFolders["msgfolderroot"]
.Request()
.GetAsync();
}..

Answer 1

Found the answer from the GitHubs docs eventually although it did take some experimentation finding out that the header option name is "User-Agent"
You create an options list and add in the user agent option
List<Option> theOptions = new List<Option>();
theOptions.Add(new HeaderOption("User-Agent", "MyUserAgentName"));
Then every .Request() call has to have the options as a parameter e.g.
rootFolder = await graphClient.Me.MailFolders["msgfolderroot"]
.Request(theOptions)
.GetAsync();