How to tell Azure.AI.OpenAI to use Vector Search

How to tell Azure OpenAi to use vector search like we do in playground .

I am using Nuget Azure.AI.OpenAI 2.1.0

I have tried adding QueryType, Inscpe and VectorizationSource vbut got 400 bad request.

    options.AddDataSource(new AzureSearchChatDataSource()

    {

        Endpoint = new Uri(azureSearchSettings.SearchEndpoint),

        IndexName = azureSearchIndex,

        QueryType  = "vector_semantic_hybrid",

        InScope = true,

        VectorizationSource  = DataSourceVectorizer.FromDeploymentName("text-embedding-ada-002"),

remark: native webrequest HTTP POST to https://xxxxx.openai.azure.com/openai/deployments/gpt-4o/chat/completions?api-version=2024-05-01-preview work fine