How i send data from .js to .vue

Question

How can I send data from a function in a .js file to a .vue

File .js

function editCoupon(id) {
    window['coupon_id'] = id
    coupon_id = id
}

File .vue

export default {
    components: {},
    data() {
        return {
            coupon_id: null,
        }
    },
    created() {
    },
    methods: {
    },
}

I want coupon_id in .vue has id of function editCoupon