Blazor不能直接进行FTP请求，但可以通过C#代码进行FTP操作。可以使用System.Net.FtpClient NuGet包，该包提供了一个FtpClient类，可实现FTP请求。以下是一个简单的示例：

using System.Net.FtpClient;

public async Task FtpDownloadAsync(string ftpUrl, string username, string password, string remoteFilePath, string localFilePath)
{
    using (var ftpClient = new FtpClient())
    {
        ftpClient.Host = ftpUrl;
        ftpClient.Credentials = new System.Net.NetworkCredential(username, password);
        
        using (var ftpStream = await ftpClient.OpenReadAsync(remoteFilePath))
        {
            using (var fileStream = new FileStream(localFilePath, FileMode.CreateNew))
            {
                await ftpStream.CopyToAsync(fileStream);
            }
        }
    }
}

在Blazor中调用该方法即可进行FTP下载：

string ftpUrl = "ftp://example.com";
string username = "ftpuser";
string password = "ftppassword";
string remoteFilePath = "/remote/path/file.txt";
string localFilePath = "file.txt";

await FtpDownloadAsync(ftpUrl, username, password, remoteFilePath, localFilePath);