Kendo UI自动完成多项选择

Question

我正在尝试将大量数据（约20万条记录）绑定到kendo UI自动完成多选字段，但仅在用户键入3个以上字符后才想运行服务器查询（通过angularJS控制器）。仅在用户键入3个字符后如何调用控制器，而不是在用户没有输入数据时在初始阶段获取所有数据

HTML代码

$scope.selectOptions = {
                placeholder: "Search Claim...",
                dataTextField: "Name",
                dataValueField: "Id",
                valuePrimitive: true,
                autoBind: false,
                filter: "startswith",
                
                dataSource: {
                    //type: "odata",
                    
                    serverPaging: true,
                    pageSize: 10,
                    transport: {
                        serverFiltering: true,
                        minLength: 3,
                        read: {
                            url: "/Login/Configuration/GetClaims",
                            type: 'GET',
                            dataType: 'json'
                        }
                    }

                }
            };

<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.7.5/angular.min.js"></script>
<select kendo-multi-select k-options="selectOptions" k-ng-model="selectedIds" class="form-control"></select>