Add or change a value of JSON key with javascript in ember not working

In .hbs file I'm trying to open a popup and using the code which contains

1.
2 ....
3 ....<div class="mdl-cell mdl-cell-6-col ">
4 ........
5 ............<p>UPDATE ID Proof</p>
6 ........
7 ........
8 ............<p>ADD ID Proof</p>
9 ........
10 ....</div>
11

So, now I'm trying to change the value of id_update_status in corresponding JS file using something like this.adultJsonArr[0].id_update_status = 'updated' So, it's not working. Instead if I try to change any other attribute it works like this.adultJsonArr[0].id_update_status_check = 'Is it working?' it works. It's basically like the json attribute which is not used at line no 4 and 7 in popup can be updated but one being used can't.