Create a custom dropdown component with checkboxes in angular

Question

I want to create a dropdown using angular multi checkbox, but I'm not sure how to do it in the "Angular way", that component will use in some places as a form control.

<app-custom-dropdown label="Group List" [options]="groupOptions" formControlName="groupsList"></app-custom-dropdown>

elected: any = [];
  disabled = false;
  private onTouched!: Function;
  private onChanged!: Function;

  public checkedOptions: any = [];


  

  writeValue(value: any): void {
    this.selected.push(value);
    console.log(this.selected);
  }

  registerOnChange(fn: any): void {
    this.onChanged = fn;
  }

  registerOnTouched(fn: any): void {
    this.onTouched = fn;
  }