LED on Pin 13; Arduino UNO

hello everyone

so far I didn't have a problem with putting an LED into pin 13 and GND but now it seems that it is on constantly while the blinking only occurs on the LED that is directly on the board. it seems that I don't get to the LED that is attached to it but that the information (HIGH/LOW) is only used by the pin directly on the board...does anyone know how to fix this bug?

thanks!

You need to put a resistor in line with any external LED and that includes pin 13. If not you could damage the LED or Arduino.

As always, we would need a clear photograph of your setup and a copy of the complete sketch code you are using, in order to figure out what else you are doing wrong.