Fixed?

00-Lesson-Site/frontend/astro.config.mjs

@@ -21,5 +21,11 @@ export default defineConfig({
 				},
 			},
 		},
+		server: {
+			host: true,
+			port: 4321,
+			strictPort: true,
+			allowedHosts: ["leafpig.mangopig.tech"], //Remember to add domain here if deploying
+		},
 	},
 });