Add axios-retry for Vercel integration for now

backend/src/config/request.ts

@@ -0,0 +1,16 @@
+import axios from 'axios';
+import axiosRetry from 'axios-retry';
+
+const axiosInstance = axios.create();
+
+// add retry functionality to the axios instance
+axiosRetry(axiosInstance, {
+  retries: 3,
+  retryDelay: (retryCount) => retryCount * 1000, // delay between retries (in milliseconds)
+  retryCondition: (error) => {
+    // only retry if the error is a network error or a 5xx server error
+    return axiosRetry.isNetworkError(error) || axiosRetry.isRetryableError(error);
+  },
+});
+
+export default axiosInstance;