I want to add User to a Group but I don't have the User's `id`, I only have the email address.

Here is the code:

```
User userToAdd = await graphClient
    .Users["objectID"]
    .Request()
    .GetAsync();

await graphClient
    .Groups["groupObjectID"]
    .Members
    .References
    .Request()
    .AddAsync(userToAdd);

```

Can someone help how do I retrieve ObjectId (User ID) from an email address using Microsoft Graph?