diff --git a/src/api/api.ts b/src/api/api.ts
index 68c308ffe..0fe9a6ccf 100644
--- a/src/api/api.ts
+++ b/src/api/api.ts
@@ -18,9 +18,18 @@ export const getChatCompletion = async (
   if (isAzureEndpoint(endpoint) && apiKey) {
     headers['api-key'] = apiKey;
 
-    const model = config.model === 'gpt-3.5-turbo' ? 'gpt-35-turbo' : config.model === 'gpt-3.5-turbo-16k' ? 'gpt-35-turbo-16k' : config.model;
+    const modelmapping = {
+      'gpt-3': 'gpt3',
+      'gpt-3.5-turbo': 'gpt-35-turbo',
+      'gpt-3.5-turbo-16k': 'gpt35-turbo-16k',
+      'gpt-4': 'gpt4-4',
+      'gpt-4-32k': 'gpt4-4-32k',
+    }
+
+    const model = modelmapping[config.model] || config.model
 
-    const apiVersion = '2023-03-15-preview';
+    // set api version to 2023-07-01-preview for gpt-4 and gpt-4-32k, otherwise use 2023-03-15-preview
+    const apiVersion = model === 'gpt4-4' || model === 'gpt4-4-32k' ? '2023-07-01-preview' : '2023-03-15-preview'
 
     const path = `openai/deployments/${model}/chat/completions?api-version=${apiVersion}`;
 
@@ -63,10 +72,18 @@ export const getChatCompletionStream = async (
   if (isAzureEndpoint(endpoint) && apiKey) {
     headers['api-key'] = apiKey;
 
-    const model = config.model === 'gpt-3.5-turbo' ? 'gpt-35-turbo' : config.model === 'gpt-3.5-turbo-16k' ? 'gpt-35-turbo-16k' : config.model;
+    const modelmapping = {
+      'gpt-3': 'gpt3',
+      'gpt-3.5-turbo': 'gpt-35-turbo',
+      'gpt-3.5-turbo-16k': 'gpt35-turbo-16k',
+      'gpt-4': 'gpt4-4',
+      'gpt-4-32k': 'gpt4-4-32k',
+    }
 
-    const apiVersion = '2023-03-15-preview';
+    const model = modelmapping[config.model] || config.model
 
+    // set api version to 2023-07-01-preview for gpt-4 and gpt-4-32k, otherwise use 2023-03-15-preview
+    const apiVersion = model === 'gpt4-4' || model === 'gpt4-4-32k' ? '2023-07-01-preview' : '2023-03-15-preview'
     const path = `openai/deployments/${model}/chat/completions?api-version=${apiVersion}`;
 
     if (!endpoint.endsWith(path)) {
@@ -89,6 +106,7 @@ export const getChatCompletionStream = async (
   });
   if (response.status === 404 || response.status === 405) {
     const text = await response.text();
+    
     if (text.includes('model_not_found')) {
       throw new Error(
         text +
diff --git a/src/hooks/useSubmit.ts b/src/hooks/useSubmit.ts
index 3240f4143..cd6efc5aa 100644
--- a/src/hooks/useSubmit.ts
+++ b/src/hooks/useSubmit.ts
@@ -122,7 +122,7 @@ const useSubmit = () => {
               if (typeof curr === 'string') {
                 partial += curr;
               } else {
-                const content = curr.choices[0].delta.content;
+                const content = curr.choices[0]?.delta?.content ?? null;
                 if (content) output += content;
               }
               return output;