This is a .net core console example executing XMLA, I am sure it works.
using Microsoft.AnalysisServices;
using System;
namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
            Server OlapServer = new Server();
            string connStrOlap = "Provider=MSOLAP.4; Data     Source=http://localhost/olap/msmdpump.dll; Catalog=YourCatalog;";
            OlapServer.Connect(connStrOlap);
            string XMLACommand = @"
<Batch xmlns=""http://schemas.microsoft.com/analysisservices/2003/engine"">
    <Parallel>
        .......Your XML content.......
    </Parallel>
</Batch>
     
                ";
        
            var result = OlapServer.Execute(XMLACommand);
            OlapServer.Disconnect();
            OlapServer.Dispose();
            Console.ReadKey();
        }
    }
}
be sure to install nuget package:(now they are preview version)
Microsoft.AnalysisServices.NetCore.retail.amd64
Microsoft.AnalysisServices.AdomdClient.NetCore.retail.amd64