vue Cannot use import statement outside a module

This error usually occurs when you try to use an "import" statement in a JavaScript file that is not recognized as a module. In Vue.js, you can use the "import" statement inside a component file, but not in the main.js file or other non-module files.

To fix this issue, you have a few options:

1. Make sure that you are using a module bundler like webpack or browserify, which can handle module imports and exports.

2. If you are using a single file component (SFC) in Vue.js, make sure that the "lang" attribute of the script tag is set to "ts" or "js" (e.g., `<script lang="ts">` or `<script lang="js">`) to indicate that it is a JavaScript module.

3. If you are working with plain JavaScript files, you can use the "require" function instead of the "import" statement to import modules. For example:

const Vue = require('vue');

Remember to also check if you have properly set up your build system and configured your project to handle modules correctly.