Add @vercel/speed-insights dependency and injectSpeedInsights in layout.server.ts

src/routes/+layout.server.ts

@@ -1,8 +1,10 @@
 import type { LayoutServerLoad, PageServerLoad } from "./$types";
-
 import { inject } from "@vercel/analytics";
+import { injectSpeedInsights } from "@vercel/speed-insights/sveltekit";
+
 if (process.env.USING_VERCEL === "true") {
   inject();
+  injectSpeedInsights();
 }
 
 export const load: LayoutServerLoad = async (event) => {