ExtJS Modern 7.0 combobox with paging how to set value?

Question

ExtJS 7.0 modern. How to set value with paging ?

xtype: 'combobox',
                    bind: {
                        store: '{contracts}',
                        value: '{record.contract_id}'
                    },
                    displayTpl: Ext.create('Ext.XTemplate',
                        '<tpl for=".">',
                            '{contract_number} - {contact_person}',
                        '</tpl>'
                    ),
                    itemTpl: '<div lass="x-boundlist-item">{contract_number} - {contact_person}</div>',
                    queryMode: 'remote',
                    label: Lang.app.contracts,
                    pageSize: 50,
                    valueField: 'id',
                    forceSelection: true,
                    minChars: 1,
                    value: 43,
                    name: 'contract_id',
                    displayField: 'contact_person',
                    floatedPicker: {
                        variableHeights: true,
                        plugins: {
                            listpaging: {
                                bufferZone: 50,
                                autoPaging: false
                            }
                        }
                    }

setValue method doesn't help. What is the correct way how to do it ? Is there possible use pagingtoolbar as classic ?