Getter and Setter in checkbox angular

I have two pages, namely view all and filter page on the filter page I have a checkbox list, when I click the show all button it will display the data according to the filter that was checked, and this is going well

I want to make a checkbox if after I click button show all, the checkbox value that is checked remains in the list, I think there must be a setter and getter in the checkbox , but I am confused how to make it... what I have created now is when I click show all, after displaying the data according to the checked list and I enter the list page, the list is empty, nothing is checked

filterpage.html

<li *ngFor="let source of sourcesList"><ion-checkbox class="checkbox" [(ngModel)]="source.checked" ></ion-checkbox></li>

to get the value as checked I use this code in .ts

 for(let item of this.sourcesList){
        if(item.checked == true){
          params = item.sourceName;
        }
      }

but how to do it so that when it displays the filter list again, it will be checked according to the previous tick a.k.a (not refreshed)??