Search an array – Javascript [duplicate]

the below code gives “The number doesn’t exist” even when input value matches. Thank you!

<input type=”number” placeholder=”Phone” id=”phone” onkeyup=”myfunction()”>
<div id=”msg” style=”color:red;”></div>

<script>
function myfunction() {
var phone = document.getElementById(“phone”).value;
var array = [[0123456], [0789]];

if (array.flat().indexOf(phone) != -1) {
document.getElementById(“msg”).innerHTML = “The number already exists”;
}else {
document.getElementById(“msg”).innerHTML = “The number doesn’t exist”;
}
}
</script>