Program.cs

using Microsoft.Azure.Storage;
using Microsoft.Azure.Storage.File;
using System;

class Program
{
    const string ConnectionString = "UseDevelopmentStorage=true";
    const string ShareReferenceName = "something";

    static void Main(string[] args)
    {
        var uploadUri = CreateTemporaryUploadUri("jon.txt");

        // Client code
        var cloudFile = new CloudFile(uploadUri);
        cloudFile.UploadText("abc");
    }

    // Server code
    static Uri CreateTemporaryUploadUri(string fileName)
    {
        var storageAccount = CloudStorageAccount.Parse(ConnectionString);

        var fileClient = storageAccount.CreateCloudFileClient();

        var shareReference = fileClient.GetShareReference(ShareReferenceName);

        var file = shareReference.GetRootDirectoryReference().GetFileReference(fileName);
        var signature = file.GetSharedAccessSignature(new SharedAccessFilePolicy
        {
            Permissions = SharedAccessFilePermissions.Create | SharedAccessFilePermissions.Write,
            SharedAccessExpiryTime = DateTimeOffset.UtcNow.AddMinutes(5)
        });

        return new UriBuilder(file.Uri)
        {
            Query = signature
        }.Uri;
    }
}

Program.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Azure.Storage.File" Version="11.1.6" />
  </ItemGroup>

</Project>