Ag Grid and Angular, how to do server side pagination?

I'm trying to do server side pagination with Ag Grid (version 25.3.0), but it's seem not to be that easy. I have a button with a click event that you trigger the search with a reactive form.

That is what I have until now:

HTML

<ag-grid-angular #agGrid 
   class="ag-theme-alpine" 
   [rowData]="dataSource.content" 
   domLayout=autoHeight 
   [columnDefs]="columns"
   [gridOptions]="gridOptions"
  (gridReady)="onGridReady($event)"
>
</ag-grid-angular>

<button (click)="doSearch()"> Search </button>

TS

     @ViewChild(AgGridAngular) agGrid!: AgGridAngular;
    
      gridOptions: GridOptions = {
        pagination: true,
        rowModelType: 'infinite',
        cacheBlockSize: 10,
        paginationPageSize: 10
      };
    
      this.form = this.fb.group({
         entityCode: [{ value: null, disabled: true }],
         businessUnitId: [null],
         firstName: [null],
         lastName: [null],
         mail: [null],
         isActive: [null],
       })
    
    
    
     doSearch() {
    const formClone = this.form?.getRawValue();

    this.dataSource = {
      getRows: (params: IGetRowsParams) => {
        this._userService?.getUsers(formClone).subscribe(data => {
          params.successCallback(
            data, data.totalElements
          );
        })
      }
    }
  }

  onGridReady(params: any) {
    this.agGrid.api.setDatasource(this.dataSource)
  }

I have no error in the console and I have no request to the service.

I think I have to put the getRows method inside the doSearch method, but I don't how to do this in the right way.