fix no tag logic

src/main.ts

@@ -22,6 +22,8 @@ let mainMountElement = document.getElementById('app');
 if (!mainMountElement) {
   mainMountElement = document.createElement('div');
   mainMountElement.id = 'app';
+
+  document.body.append(mainMountElement);
 }
 
 export default async ({ apps: rawApps, navigations, config, features }) => {