I booked a plane ticket online. Can I go directly to the airport to board the plane after receiving the SMS?

Yes, but remember to bring your ID card or passport to board the plane. In other words, you have to change tickets at the electronic ticket exchange office of the corresponding airline at the airport, and you can board the plane only if you have a ticket. It is impossible to use only electronic tickets. In addition, if you don't have a pre-selected seat when you buy an e-ticket, you can consult and choose a seat among the remaining seats when you change your ticket. Don't forget to check your luggage.