diff --git a/src/Infrastructure/BotSharp.OpenAPI/Controllers/InstructModeController.cs b/src/Infrastructure/BotSharp.OpenAPI/Controllers/InstructModeController.cs
index 0b5de0ad6..2189af2f6 100644
--- a/src/Infrastructure/BotSharp.OpenAPI/Controllers/InstructModeController.cs
+++ b/src/Infrastructure/BotSharp.OpenAPI/Controllers/InstructModeController.cs
@@ -48,7 +48,7 @@ public async Task<string> TextCompletion([FromBody] IncomingMessageModel input)
     {
         var state = _services.GetRequiredService<IConversationStateService>();
         input.States.ForEach(x => state.SetState(x.Key, x.Value, activeRounds: x.ActiveRounds, source: StateSource.External));
-        state.SetState("provider", input.Provider, source: StateSource.External)
+        state.SetState("provider", input.Provider ?? "azure-openai", source: StateSource.External)
             .SetState("model", input.Model, source: StateSource.External)
             .SetState("model_id", input.ModelId, source: StateSource.External);
 
diff --git a/src/Plugins/BotSharp.Plugin.AzureOpenAI/Providers/Text/TextCompletionProvider.cs b/src/Plugins/BotSharp.Plugin.AzureOpenAI/Providers/Text/TextCompletionProvider.cs
index 9b41b948e..ff817b257 100644
--- a/src/Plugins/BotSharp.Plugin.AzureOpenAI/Providers/Text/TextCompletionProvider.cs
+++ b/src/Plugins/BotSharp.Plugin.AzureOpenAI/Providers/Text/TextCompletionProvider.cs
@@ -136,7 +136,7 @@ private string BuildApiUrl(LlmModelSetting modelSetting)
         var endpoint = modelSetting.Endpoint.EndsWith("/") ?
             modelSetting.Endpoint.Substring(0, modelSetting.Endpoint.Length - 1) : modelSetting.Endpoint;
 
-        url = $"{endpoint}/openai/deployments/{_model}/completions?api-version={modelSetting.Version}";
+        url = $"{endpoint}/openai/deployments/{_model}/completions?api-version=2023-09-15-preview";
         return url;
     }