docs: Add text_to_speech left out in the API response (#19862)

web/app/components/develop/template/template_advanced_chat.en.mdx

@@ -1165,6 +1165,13 @@ Chat applications support session persistence, allowing previous chat history to
       - `enabled` (bool) Whether it is enabled
     - `speech_to_text` (object) Speech to text
       - `enabled` (bool) Whether it is enabled
+    - `text_to_speech` (object) Text to speech
+      - `enabled` (bool) Whether it is enabled
+      - `voice` (string) Voice type
+      - `language` (string) Language
+      - `autoPlay` (string) Auto play
+        - `enabled`   Enabled
+        - `disabled`  Disabled
     - `retriever_resource` (object) Citation and Attribution
       - `enabled` (bool) Whether it is enabled
     - `annotation_reply` (object) Annotation reply
@@ -1220,6 +1227,12 @@ Chat applications support session persistence, allowing previous chat history to
       "speech_to_text": {
           "enabled": true
       },
+      "text_to_speech": {
+          "enabled": true,
+          "voice": "sambert-zhinan-v1",
+          "language": "zh-Hans",
+          "autoPlay": "disabled"
+      },
       "retriever_resource": {
           "enabled": true
       },