Getting error 404 when post data from local storage - php

Question

I want to retrieve data from local storage and save it to the database. But when I'm trying to post, It gives an error 404. I know the file exist because when I remove this line :
formData.append('data',array);
my post is work. However, It works on localhost not on live server.
Whats wrong with this code.
Data from localstorage :
{
"mylist":"name of list",
"list": {
"category":[ {
"name":"Category 1",
"items":[ {
"name": "Category item list 1, "amount": "0"
}
]
}
,
{
"name":"Category 2",
"items":[ {
"name": "Category item list 2, "amount": "0"
}
]
}
]
}
}
React js trigger post :
function savepackList(){
const array = localStorage.getItem('list');
let formData = new FormData();
formData.append('type','savelist');
formData.append('data',array); //removing this it does not give a 404 error
axios.post('/request.php',formData)
.then(function (response) {
console.log(response.data);
})
.catch(function (error) {
console.log(error);
});return;
}
PHP code :
if($_POST['type']=='savelist'){
$obj = json_decode($_POST['data'],true);
echo json_encode($obj);
}