Unable to retain the value of check boxes present on a dialog modal

I have modal which then has checkboxes inside it . I choose the options and the selected options works the correct way and gets back what I want. But once I close the modal(where the checboxes are present) and open it again, the values that I chose before disappears and I get a clean slate. I am fine with having a clean slate once the user refreshes the page, but it should keep the selection until then, Is there a easy way out in which I can do that. I am using Angular. Below is the screenshot of my modal