Cannot populate when I use Foreign key in mongoose - node.js

Question

I tried to join three documents in mongodb using mongoose in nodejs, but unfortunately this error occurs. My mongoose version is 6.2.3
Declaring Schema
const mongoose = require('mongoose')
const declaringSchema = mongoose.Schema({
cniDeclaring: { type: Number, required: true },
father: {
type: mongoose.Schema.Types.ObjectId,
ref: 'Father',
required: true,
},
mother: {
type: mongoose.Schema.Types.ObjectId,
ref: 'Mother',
required: true,
},
name: { type: String, required: true },
surname: { type: String, required: true },
birthDay: { type: Date, required: true },
birthPlace: { type: String, required: true },
gender: { type: String, required: true },
address: { type: String, required: true },
relationShipDeclared: { type: String, required: true },
phone: { type: Number, required: true },
request: [{
type: mongoose.Schema.Types.ObjectId,
ref: 'Request',
}],
});
module.exports = mongoose.model('Declaring', declaringSchema);
Declared Schema
const mongoose = require('mongoose')
const declaredSchema = mongoose.Schema({
name: { type: String, required: true },
surname: { type: String, required: true },
father: {
type: mongoose.Schema.Types.ObjectId,
ref: 'Father',
},
mother: {
type: mongoose.Schema.Types.ObjectId,
ref: 'Mother',
},
birthDay: { type: Date, required: true },
birthPlace: { type: String, required: true },
gender: { type: String, required: true },
nationality: { type: String, required: true },
request: {
type: mongoose.Schema.Types.ObjectId,
ref: 'Request',
},
});
module.exports = mongoose.model('Declared', declaredSchema);
Father Schema
const mongoose = require('mongoose')
const fatherSchema = mongoose.Schema({
cniFather: { type: Number, required: true },
nameP: { type: String, required: true },
surname: { type: String, required: true },
birthDay: { type: Date, required: true },
birthPlace: { type: String, required: true },
address: { type: String, required: true },
phone: { type: Number, required: true },
occupation: { type: String, required: true },
declaring: [{
type: mongoose.Schema.Types.ObjectId,
ref: 'Declaring',
}],
declared: [{
type: mongoose.Schema.Types.ObjectId,
ref: 'Declared',
}],
});
module.exports = mongoose.model('Father', fatherSchema);
Now I want to get all the fathers back
const Father = require('../models/Father');
exports.createFather = (req, res, next) => {
const father = new Father({
...req.body
});
father.save()
.then(() => res.status(201).json({ message: 'Father created !'}))
.catch(error => res.status(400).json({ error })
);
}
exports.getAllFathers = (req, res, next) => {
Father.find()
.populate('declarings')
.populate('declareds')
.exec((err, res) => {
if(err){
console.log(err);
}
});
};
and I have the following error:
MongooseError: Cannot populate path declarings because it is not in your schema. Set the strictPopulate option to false to override.