where is the default value defined in the migration used sequelize code example

Example 1: sequelize migration default value

queryInterface.addColumn('OrderBackups', 'my_column', {
  type: Sequelize.INTEGER,
  defaultValue: 0
})

Example 2: sequelize migration add default value

queryInterface.addColumn('My_table', 'my_column', {
  type: Sequelize.INTEGER,
  defaultValue: 0
})