Sequelize Association Columns not generated

I'm trying to associate Products model with User model while making sure to force sync in order to ensure that the newest changes are present. I get the error that columns UserId and ProductManagerId are not created.

Why are the columns not auto-generated?

Product.js

'use strict';
/* Model ONLY for DePuy Products */
module.exports = function(sequelize, DataTypes) {
  var Product = sequelize.define('Product', {
    name: {
      type: DataTypes.STRING,
      allowNull : false
    },
    sku: {
      type:DataTypes.STRING,
      allowNull: false,
      primaryKey: true,
    },
  }, {
    classMethods: {
      associate: function(models) {
        Product.belongsTo(models.User,{ as : 'ProductManager'});
        // associations can be defined here
      }
    }
  });
      Product.sync({force: true}).then(() => {
        console.log('Sequelize forced');
      })

  return Product;
};

User.js

module.exports = (sequelize, DataTypes) => {
  const User = sequelize.define('User', {
    id: {
      type: DataTypes.INTEGER,
      autoIncrement: true,
      primaryKey: true,
      allowNull: false,
    },
    password: {
      type: DataTypes.STRING,
      allowNull: false,
    },
    email: {
      type: DataTypes.STRING,
      unique: true,
    },
  }, {
    classMethods: {
      associate: (models) => {
        // associations can be defined here
        User.hasMany(models.Product);
      },
    },
    freezeTableName: true,
  });
  // FORCE FOR NOW Use only if make model changes
    User.sync({force: true}).then(() => {
     console.log('Sequelize forced');
   })
  return User;
};

Dialect: Postgres Sequelize version: 3.30.1

Ps. I originally used sequelize-cli to generate the model file, then changed to my needs.

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