Fix: Corrected the sendActivity parameter type from an array to a single activity object

extensions/msteams/src/reply-dispatcher.ts

@@ -42,7 +42,7 @@ export function createMSTeamsReplyDispatcher(params: {
 }) {
   const core = getMSTeamsRuntime();
   const sendTypingIndicator = async () => {
-    await params.context.sendActivity([{ type: "typing" }]);
+    await params.context.sendActivity({ type: "typing" });
   };
   const typingCallbacks = createTypingCallbacks({
     start: sendTypingIndicator,