const list= [{images:'',title:'1'},{images:'',title:'2'},{images:'',title:'3'}]

const value = 'list.['+ index + ']'

    const setup = await db.collection('commodity').doc(id).update({

      data:{

        [value]:{

          images:event.images,

          title:event.title

        }

      }

    })

    return setup