This article also reviewed a programmer with a valuable <1 $. A detailed diagram of the connection of the programmer to the microcontroller is reviewed and described.
You made an error in your diagram. You have the 4K7 resistor connected to the 3.3 V pin instead of the TX pin. You have the the TX pin connected directly to the UPDI pin on the microcontroller instead of having it going through the resistor. You don't have the RX pin connected at all.I hope you will fix this soon so that it doesn't cause confusion for the people who read your tutorial and try to use your wiring diagram.