Do you know any example to upload file to a specific folder (identified by folderId)? with Graph v5.

Hello.
I'm just starting out with SharePoint and Microsoft 365.

I need to upload a file to a specific folder in a SharePoint library using Graph v5.61.
I've managed to upload it to the root of the library:

public async Task<string> UploadFile2Root(string listId, string fileName, byte[] fileBytes)
{
    string fileId = "";
    Drive? drive = await _graphClient.Sites[SITE_ID].Lists[listId].Drive.GetAsync();
    GraphSDK.Drives.Item.Root.RootRequestBuilder targetFolder = _graphClient.Drives[drive?.Id].Root;
    using (MemoryStream stream = new MemoryStream(fileBytes))
    {
        await targetFolder
                    .ItemWithPath(fileName)
                    .Content
                    .PutAsync(stream);
        DriveItem? uploadedItem = await targetFolder.ItemWithPath(fileName).GetAsync();
        fileId = uploadedItem?.Id ?? "";
    }
    return fileId;
}

The problem is when I try to use a specific folder (folderId has the correct value):

var targetFolder = _graphClient.Drives[drive?.Id].Items[folderId];

I always get the error: "Microsoft.Graph.Models.ODataErrors.ODataError: 'The resource could not be found.'"

Could you tell me how to solve the problem or an example that does this task?

I have also tried: https://learn.microsoft.com/en-us/answers/questions/1517434/how-to-upload-a-file-to-a-sharepoint-driveitem-fol and other examples, but without success.
I'm also trying to retrieve something similar to an ItemRequestBuilder.

Thank you very much in advance.