Programatically create search index not working (C#)

MongoDB Atlas Atlas Search
,
1

Following guide from here: https://www.mongodb.com/docs/atlas/atlas-search/create-index/

Executing this command:

using MongoDB.Bson;
using MongoDB.Driver;
// connect to your Atlas deployment
var uri = "<connection-string>";
var client = new MongoClient(uri);
var db = client.GetDatabase("<databaseName>");
var collection = db.GetCollection<BsonDocument>("<collectionName>");
// define your Atlas Search index
var index = new BsonDocument
{
  { "mappings", new BsonDocument
    {
      { "dynamic", true }
    }
  }
};
var result = collection.SearchIndexes.CreateOne(index);
Console.WriteLine(result);

gave me an exception:

MongoDB.Driver.MongoCommandException: Command createSearchIndexes failed: command not found.
   at MongoDB.Driver.Core.WireProtocol.CommandUsingCommandMessageWireProtocol`1.ProcessResponse(ConnectionId connectionId, CommandMessage responseMessage)
   at MongoDB.Driver.Core.WireProtocol.CommandUsingCommandMessageWireProtocol`1.ExecuteAsync(IConnection connection, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Servers.Server.ServerChannel.ExecuteProtocolAsync[TResult](IWireProtocol`1 protocol, ICoreSession session, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Operations.CommandOperationBase`1.ExecuteProtocolAsync(IChannelSource channelSource, ICoreSessionHandle session, ReadPreference readPreference, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Operations.WriteCommandOperation`1.ExecuteAsync(IWriteBinding binding, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Operations.CreateSearchIndexesOperation.ExecuteAsync(IWriteBinding binding, CancellationToken cancellationToken)
   at MongoDB.Driver.OperationExecutor.ExecuteWriteOperationAsync[TResult](IWriteBinding binding, IWriteOperation`1 operation, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.ExecuteWriteOperationAsync[TResult](IClientSessionHandle session, IWriteOperation`1 operation, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.UsingImplicitSessionAsync[TResult](Func`2 funcAsync, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.MongoSearchIndexManager.CreateManyAsync(IEnumerable`1 models, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.MongoSearchIndexManager.CreateOneAsync(CreateSearchIndexModel model, CancellationToken cancellationToken)
.....

I can create the index through Atlas manually just fine.

I’m using c# MongoDB Driver Version=2.24.0
``