To deploy your nuxt.js app you need to follow the below workaround :
Please make sure that you have add the following in your package.json
"scripts": {
"dev": "nuxt dev",
"build": "nuxt generate"
},
- If the website does note immediately load, then the background GitHub Actions workflow is still running. Once the workflow is complete you can then click refresh the browser to view your web app.
To check the status you can navigate as shown below or you can use this https://github.com/<YOUR_GITHUB_USERNAME>/repository name/actions

For more information please refer the below links: