Sequelize Associations Error Users.hasMany called with something that's not a subclass of Sequelize.Model. when associating between 2 models

I am encountering an error Users.hasMany called with something that's not a subclass of Sequelize.Model. when associating between 2 models (Users and Comments). BUT when i remove const Users = require("./user"); and Comments.belongsTo(Users, { foreignKey: "userId", onDelete: "cascade", });
from the Comments model i instead get "Users is not associated to Comments!" error. I already associated it in the users model.

This is my model for Comments:

const { DataTypes } = require("sequelize");
const { sequelize } = require(".");
const Users = require("./user");

const Comments = sequelize.define("Comments", {
    comment: {
        type: DataTypes.STRING,
        allowNull: false,
        validate: {
            min: 1,
            max: 50,
        },
    },
});
// If i remove this from the code i instead get Users is not associated to Comments!

Comments.belongsTo(Users, {
    foreignKey: "userId",
    onDelete: "cascade",
});

//

module.exports = Comments;

This is my Users model:

const { DataTypes } = require("sequelize");
const { sequelize } = require(".");
const Comments = require("./comment");
const jwt = require("jsonwebtoken");

const Users = sequelize.define("Users", {
    username: {
        type: DataTypes.STRING,
        allowNull: false,
        unique: true,
        validate: {
            min: 5,
            max: 30,
            notNull: true,
        },
    },
});

Users.hasMany(Comments, {
    foreignKey: "userId",
    onDelete: "cascade",
});

module.exports = Users;

I also have a GET request for retrieving all comments where I would like to include the Users table so that I have access to the username of the user that created that comment:

const getComments = async (req, res) => {
    const comments = await Comments.findAll({
        include: Users,
    });
    res.send(comments);
};

You could define a separate global method for handling associations:

const Users = require("./user");
const Comments = require("./comment");

const sequelize = new Sequelize(...);

export const sync = async () => {
    Comments.belongsTo(Users, {
        foreignKey: "userId",
        onDelete: "cascade",
    });

    Users.hasMany(Comments, {
        foreignKey: "userId",
        onDelete: "cascade",
    });

    await sequelize.sync();
}

Then, use it when initializing the database/application:

import { sync } from './path/to/sync';

await sync();

This will ensure both models are defined when associated.