How to include a separate .js file in a vue project?

Question

Vue.js

Please explain how to include a separate .js file in the vue project?
Installed vue and vue-router via npm
There is a green.js file
In which file and what should I write in order for the project to accept it?
I tried to add to index.html

<script v-if="green" async defer src="./src/assets/js/green.js"></script>

and in App.vue file
export default {
name: 'App',
green: true
}
But nothing works((
Please explain

Answer 1

not?
import './src/assets/js/green.js'