Getting data from another table in the database

I have two models in database, user and post

const User = sequelize.define('user', {
    id: {type: DataTypes.INTEGER, primaryKey: true, autoIncrement: true},
    email: {type: DataTypes.STRING, unique: true},
    password: {type: DataTypes.STRING},
});

const Post = sequelize.define('post', {
    author: {type: DataTypes.STRING},
    title: {type: DataTypes.STRING},
    content: {type: DataTypes.STRING}
});

And there is a method that creates a user post:

async createPost(req,res) {
        try {
            console.log(req.headers.authorization);
            const {author} = await User.findOne({where: {email}});
            const {title, content} = req.body;
            /*if(!title || !content) {
                return res.status(400).json({message: 'Title or content cannot be empty'});
            }
            const post = await Post.create({})*/
            return res.json({message: 'All right'});
        } catch (e) {
            console.log(e.message);
        }
    }
}

How do I get the user's email from another table and store it in the author variable. Only a registered user can write a post. There was an option using jwt-decode to decrypt the jwt token and find the email field there, but can it be simpler?