In my case I only want get a number to use it. This is my schema:

const personaSchema = mongoose.Schema({
    nombre:String,
    direccion: String,
    dineroRecibido: Number,
    fecha: String
},{versionKey: false})

this is my aggregate function:

const mostrarSumaDinerosPorDia = async (fecha) =>{
    const sumaDineroHoy = await PersonaModel.aggregate(
      [
          {$match:{fecha:fecha}},
          {$group:{_id:'$fecha'   ,total:{$sum:'$dineroRecibido'}}}
      ]  
    
    )
   
    console.log(sumaDineroHoy)
}

and this is my answer console:

[ { _id: '24 de diciembre del 2021', total: 10000 } ]

I only want get 10000, no more.