mysql – Confusion in the Nodejs passport configuration

I have tried to configure my MySQL database configuration Nodejs. I found this configuration passport.js for MySQL on Github. The configuration is working properly but there is one part that I do not understand.

var insertQuery = "INSERT INTO users (email, password) values ​​(" + email + "," + password + ")";
console.log (insertQuery);
connection.query (insertQuery, function (err, rows)) {
newUserMysql.id = rows.insertId;

return done (null, newUserMysql);
}); 

I'm confused about the insertid field. The table I'm using has no field called insertID. However, it has a field named ID. I've tried to change this line for

newUserMysql.id = rows.Id;

but it gives me:

Error: Failed to serialize user in session

To leave it as it is does not give me any error

Looks like insertid has nothing to do with the ID field of my table but I do not understand what it means