mat-autocomplete drop down in alphabetic order

Question

I need put the autocomplete in alphabetic order. How I do this? The autocomplete como from a database and is selected by ID. How can I reorder to alphabetic? I try

     this.gestorService = this.getGestores.sort((a,b) => {
       if(a.viewValue < b.viewValue) { return -1; }
       if(a.viewValue > b.viewValue) { return 1; }
   })

But I don't know where I can put this code. And sort come with a error

Property 'sort' does not exist on type '() => void'

my component.html

    <mat-label>Gestor</mat-label>
<input type="text"
      matInput
       formControlName="gestor"
       [matAutocomplete]="autoGestor"
       [(ngModel)]="ped.gestor"
       required>
<mat-autocomplete #autoGestor="matAutocomplete"
                  [displayWith]="selectGestor">

    <mat-option *ngFor="let gestor of filteredGestores  | async"
                [value]="gestor">
        {{gestor.colaborador?.nome}}
    </mat-option>
</mat-autocomplete>

my ts

getGestores() {

this.gestorService.getAll().subscribe({
  next: gestores => {
    this.gestores = gestores;
    this.filteredGestores = this.pedForm.get('gestor').valueChanges
      .pipe(
        startWith(''),
        map((value) => {
          console.log(value);
          return this._filterGestor(value);
        }
        )
      );
  }
})
}