I have 2 table schemas Customer and Cart

Customer.js

module.exports = (sequelize, DataTypes) => {
    const Customer = sequelize.define("custom", {
        id: {
            type: DataTypes.INTEGER,
            autoIncrement: true,
            primaryKey: true
        },
        title: {
            type: DataTypes.STRING,
            allowNull: false
        },
        username: {
            type: DataTypes.STRING,
            allowNull: false
        },
        email: {
            type: DataTypes.STRING,
            allowNull: false
        },
        password: {
            type: DataTypes.STRING,
            allowNull: false
        },
        address: {
            type: DataTypes.STRING,
            allowNull: true
        },
        date: {
            type: DataTypes.STRING,
            allowNull: false,
        }
    }, {
        timestamps: false
    });

    Customer.associate = (models) => {
        Customer.hasOne(models.cart, { foreignKey: 'customerId' });
    };

    return Customer;
};

Cart.js

module.exports = (sequelize, DataTypes) => {
    const Cart = sequelize.define("cart", {
        id: {
            type: DataTypes.INTEGER,
            autoIncrement: true,
            primaryKey: true
        },
        customerId: {
            type: DataTypes.INTEGER,
            allowNull: false,
            references: {
                model: 'custom',
                key: 'id'
            }
        }

    }, {
        timestamps: false
    });

    Cart.associate = (models) => {
        // Define associations here
        Cart.belongsTo(models.customer, { foreignKey: 'customerId' });
    };

    return Cart;
};

I have index.js file for each models

customer/index.js

const dbConfig = require("../../config/db.config.js");

const Sequelize = require("sequelize");
const sequelize = new Sequelize(dbConfig.DB, dbConfig.USER, dbConfig.PASSWORD, {
    host: dbConfig.HOST,
    dialect: dbConfig.dialect,
    operatorsAliases: false,

    pool: {
        max: dbConfig.pool.max,
        min: dbConfig.pool.min,
        acquire: dbConfig.pool.acquire,
        idle: dbConfig.pool.idle
    }
});

const db = {};

db.Sequelize = Sequelize;
db.sequelize = sequelize;

db.customer = require("./customer.js")(sequelize, Sequelize);
db.cart = require("../cart/cart.js")(sequelize, Sequelize);
db.customer.associate(db);
module.exports = db;

cart/index.js

const dbConfig = require("../../config/db.config.js");

const Sequelize = require("sequelize");
const sequelize = new Sequelize(dbConfig.DB, dbConfig.USER, dbConfig.PASSWORD, {
    host: dbConfig.HOST,
    dialect: dbConfig.dialect,
    operatorsAliases: false,

    pool: {
        max: dbConfig.pool.max,
        min: dbConfig.pool.min,
        acquire: dbConfig.pool.acquire,
        idle: dbConfig.pool.idle
    }
});

const db = {};

db.Sequelize = Sequelize;
db.sequelize = sequelize;

db.cart = require('./cart.js')(sequelize, Sequelize);
db.customer = require('../customer/customer.js')(sequelize, Sequelize);
db.customer.associate(db);
module.exports = db;

and my server.js or the main file I am running

const express = require('express');
const cors = require("cors");
const session = require('express-session');
const crypto = require('crypto');
const app = express();

var corsOptions = {
    origin: "http://localhost:3000"
};

app.use(cors(corsOptions));
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

// Generate a random secret key
const secretKey = crypto.randomBytes(32).toString('hex');

app.use(session({
    secret: secretKey,
    resave: false,
    saveUninitialized: false
}));

const db_customer = require("./app/database/models/customer/index.js");
// const db_product = require("./app/database/models/product/index.js");

// db.sequelize.sync();
db_customer.sync();
const PORT = 4000;
app.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}.`);
});

after running node server.js

i am getting this error
at Socket.emit (node:events:518:28)
at addChunk (node:internal/streams/readable:559:12)
at readableAddChunkPushByteMode (node:internal/streams/readable:510:3)
at Readable.push (node:internal/streams/readable:390:5) {
code: ‘ER_CANT_CREATE_TABLE’,
errno: 1005,
sqlState: ‘HY000’,
sqlMessage: ‘Can’t create table s3941488_fsd_a2.carts (errno: 150 “Foreign key constraint is incorrectly formed”)’,
sql: ‘CREATE TABLE IF NOT EXISTS carts (id INTEGER auto_increment , customerId INTEGER NOT NULL, PRIMARY KEY (id), FOREIGN KEY (customerId) REFERENCES custom (id) ON DELETE CASCADE ON UPDATE CASCADE) ENGINE=InnoDB;’,
parameters: undefined
},
sql: ‘CREATE TABLE IF NOT EXISTS carts (id INTEGER auto_increment , customerId INTEGER NOT NULL, PRIMARY KEY (id), FOREIGN KEY (customerId) REFERENCES custom (id) ON DELETE CASCADE ON UPDATE CASCADE) ENGINE=InnoDB;’,
parameters: {}
}

It fixed the issue when I removed the references attribute from customerId attribute in the cart model schema, but I require for data integrity. I am not sure what causes the problem