How to align or change the position of a virtual field

let assignedToField = form.addField({
                    id: 'custpage_assigned_to',
                    type: serverWidget.FieldType.SELECT,
                    label: 'Assigned To',
                });

                form.insertField({
                    field: assignedToField,
                    nextfield: 'custrecord_jj_status_ahap1473'
                });