add data to array delete other content

i´m traying to add element into array without delete other content, it´s very trivial... Array.push()

my problem it´s i´m using ref([]) and i´m reading that i can use ref.value.push = newItem

but my problem it´s that override my previous content... i need to do that user select checkbox with information, and this information be added to my table. To build this, i´m doing:

<input type="checkbox" :id="item.id" :name="item.name" :data-category="item.category.name" style="font-size: 0.6em; transform: scale(1.6);" @change="addToCart($event)"/>

and my function addToCart():

const addItemCart = ref([])
    const addToCart = (event) => {
        let itemId = event.target.id
        let itemName = event.target.name
        let category = event.target.getAttribute("data-category")

        var newItem = new Array();
        newItem = [{ id: itemId, name: itemName, category: category }];
             
        addItemCart.value = newItem
    }

i trayed with:

const addItemCart = ref([])
    const addToCart = (event) => {
        let itemId = event.target.id
        let itemName = event.target.name
        let category = event.target.getAttribute("data-category")

        var newItem = new Array();
        newItem = [{ id: itemId, name: itemName, category: category }];
             
        addItemCart.value.push = newItem
        console.log(addItemCart.value)
    }

This return:

Proxy(Array) {push: Array(1)}

[[Handler]]:Object
[[Target]]: Array(0)
push: Array(1)
0: {id: '96', name: 'DESINCRUSTADOR DCALUXE - HIDROCAL ELECTRONICO', category: 'ARTICULOS B'}
length: 1
[[Prototype]]: Array(0)
length: 0
[[Prototype]]: Array(0)
[[IsRevoked]]: false
app.js:20948 

Proxy(Array) {push: Array(1)}
[[Handler]]: Object
[[Target]]: Array(0)
push: Array(1)
0: {id: '281', name: 'DCALUXE PRO 2.0 DESINCRUSTADOR ELECTRONICO', category: 'ARTICULOS B'}
length: 1
[[Prototype]]: Array(0)
length: 0
[[Prototype]]: Array(0)
[[IsRevoked]]: false

Not push data in my array and i can´t show my data in my table, i have this code to do loop:

<tr v-for="item in addItemCart" :key="item">
    <td>{{ item }}</td>
    <td>{{ item.id }}</td>
    <td>{{ item.name }}</td>
    <td>{{ item.category }}</td>
    <td><i class="fa fa-trash" aria-hidden="true" @click="removeItem($event)"></i></td>
</tr>

My question it´s, how i can to do add items in my array bu not deleted my other content.

Thanks for readme and sorry for my bad english

try using push as a function, and passing the new object to push as a parameter:

const addItemCart = ref([])
const addToCart = (event) => {
    let itemId = event.target.id
    let itemName = event.target.name
    let category = event.target.getAttribute("data-category")
          
    addItemCart.value.push({ id: itemId, name: itemName, category: category })
    //here we push the new item as an object into `addItemCart.value`
}