How to perform a one-to-one migration

Question

I have a particular case where I have a promotion and a survey attached to it. The thing is don't want the promotion to have FKs for surveys as the surveys can be optional, but I also don't want to store the survey data inside the promotion since it's optional, the survey is always singular. I want to create a one-to-one relationship with the sequelize migration file. But I always create a one-to-many relationship instead. Can it be limited within the migration file or only on the application side of things with model associations. Here are my migration files:

migrations/promotion.js:

'use strict';
/** @type {import('sequelize-cli').Migration} */
module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('Promotions', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER
      },
      establishmentId:{        
        type: Sequelize.INTEGER,
        allowNull: false,
        references: {
          model: 'Establishments',
          key: 'id'
        },
      },
      name: {
        type: Sequelize.STRING
      },
      pointPayOut: {
        type: Sequelize.DECIMAL
      },
      vidLnk: {
        type: Sequelize.STRING
      },
      imgLnk: {
        allowNull: true,
        type: Sequelize.STRING
      },
      description: {
        type: Sequelize.STRING
      },
      createdAt: {
        allowNull: false,
        type: Sequelize.DATE
      },
      updatedAt: {
        allowNull: false,
        type: Sequelize.DATE
      }
    });

    await queryInterface.addConstraint('Promotions', {
      fields: ['establishmentId'],
      type: 'foreign key',
      name: 'FK_PROMOTION_ESTABLISHMENT',
      references: {
        table: 'Establishments',
        field: 'id'
      },
      onDelete: 'CASCADE',
      onUpdate: 'CASCADE'
    });
  },
  async down(queryInterface, Sequelize) {
    await queryInterface.dropTable('Promotions');
  }
};

migrations/survey.js:

'use strict';
/** @type {import('sequelize-cli').Migration} */
module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('Surveys', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER
      },
      question: {
        type: Sequelize.STRING
      },
      promotionId: {
        type: Sequelize.INTEGER,
        allowNull: false,
        references: {
          model: 'Promotions',
          key: 'id'
        },
      },
      correctOptionId: {
        type: Sequelize.INTEGER,
        allowNull: true,
      },
      createdAt: {
        allowNull: false,
        type: Sequelize.DATE
      },
      updatedAt: {
        allowNull: false,
        type: Sequelize.DATE
      }
    });

    await queryInterface.addConstraint('Surveys', {
      fields: ['promotionId'],
      type: 'foreign key',
      name: 'FK_SURVEY_PROMOTION',
      references: {
        table: 'Promotions',
        field: 'id'
      },
      onDelete: 'CASCADE',
      onUpdate: 'CASCADE'
    });
  },
  async down(queryInterface, Sequelize) {
    await queryInterface.dropTable('Surveys');
  }
};

The Postgres ERD schema returns this: