C# Two GraphServiceClient singleton instances

In my application (.NET Web API), I need to call Microsoft Graph API using two different credentials set (completely different tenant). When I was using only one, the case was simple - I just did a setup in DI part of Program.cs:

var clientSecretCredential = new ClientSecretCredential(b2cSettings.TenantId, b2cSettings.ClientId, b2cSettings.ClientSecret, tokenCredentialOptions);

// Use a single client instance for the lifetime of the application
services.AddSingleton(sp =>
{
    return new GraphServiceClient(clientSecretCredential, new[] { "https://graph.microsoft.com/.default" });
});

which allowed me to just inject it to whichever service I needed, like so:

    public GraphApiClient(
        GraphServiceClient graphServiceClient)
    {
        _graphServiceClient = graphServiceClient;
    }

Obviously, there is no way to re-use that for second set of credentials - it will just pick the last registered GraphServiceClient instance.

It smells like some common pattern, but it does not seem to be a good candidate for factory (I want only TWO instances across app lifetime - each with different credentials). I also wonder how would service "client" (class using it) specify which GraphServiceClient to retrieve in runtime.

I imagine some "aggregate" class with methods like:

RegisterGraphApiClientWithCredentials(string tenantId, string clientId, string clientSecret); // <- this would be done once, in Program.cs

RetrieveGraphApiClientWithCredentials(string tenantId, string clientId, string clientSecret); // <- this would be done whenever some service would need actual client instance

How should I approach this problem? Microsoft advise single instance for the lifetime of the application. Will this approach collide with that?

Thank You in advance!