Inertia and vue devtools not permitted.

It looks like you're trying to enable Vue Devtools for an application that uses Vue 3 along with Inertia.js. The issue you're encountering typically happens when Vue is running in production mode, which disables Vue Devtools by default. Here are a few steps to ensure that Vue Devtools is enabled in development mode:

1. Ensure Vue is in Development Mode: The first thing to check is whether your Vue application is indeed running in development mode. This is controlled by the NODE_ENV environment variable. Make sure that NODE_ENV is set to 'development' during the build or runtime of your application. This is typically set in your webpack.config.js, vue.config.js, or through environment variables in your development environment.

2. Correctly Configure Vue Devtools: Based on your code snippet, it seems like you might be setting the configuration on the wrong object or after the app has already been mounted. Here's how you can adjust it:

import { createApp, h } from 'vue';
import App from './App.vue';
import { ZiggyVue } from 'ziggy';
import { plugin } from 'some-plugin';

const app = createApp({
  render: () => h(App)
});

// Enable Vue devtools
app.config.devtools = true;

app.use(plugin)
   .use(ZiggyVue)
   .mount('#app');

1. Check Browser Extension: Ensure that you have the Vue.js devtools extension installed in your browser. Also, make sure it is up to date. Sometimes, browser extensions can be disabled (check in the browser's extension settings).

2. Hard Refresh Your Browser: Sometimes, browsers cache JavaScript heavily. After making changes to your configuration, perform a hard refresh or clear your browser's cache to make sure the latest scripts are being loaded.

3. Review Build Tools Configuration: If you are using build tools like Webpack or Vite, review their configuration to ensure they are not setting Vue to production mode in your development environment. For example, in Webpack, you might accidentally have something like DefinePlugin setting NODE_ENV to 'production'.

Here's an example for a Webpack configuration snippet:

const webpack = require('webpack');

module.exports = {
  // other configurations...
  plugins: [
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV || 'development')
    })
  ]
};

By following these steps, you should be able to resolve the issue with Vue Devtools not being available. Make sure each part of your environment is correctly configured for development.