I am using Nodejs and using expressjs framework and now I am trying to get "Last inserted id" but I am getting "undefined" in the console, how can I get the last inserted id? This is my current code

static async addServiceDetail(salonId,serviceId,genderTypeId,price,serviceName)
    {
        const sql = `SELECT id from hc_servicesdetail WHERE shopId='${shopId}' AND serviceId='${serviceId}' AND genderTypeId='genderTypeId'`;
        const [rows, fields] = await pool.execute(sql);
        if(rows<1)
            {
                const sql2 = `INSERT INTO hc_servicesdetail (shopId, serviceId, genderTypeId,price,serviceName) VALUES ("${shopId}", "${serviceId}", "${genderTypeId}", "${price}","$ {serviceName}")`;
                const datass = await pool.execute(sql2);
                console.log('last inserted id is ' datass.insertId);
            }
        else
            {
                console.log('already exist');
            }
    }
}

module.exports = User;