Fix add_button pin selection

main/io.cpp

@@ -117,7 +117,7 @@ void add_button(gpio_num_t gpio_num, std::function<void()> on_press, std::functi
 }
 
 void add_button(gpio_num_t gpio, std::string topic, std::string message) {
-    add_button(GPIO_NUM_18, [topic, message](){ publish_message(topic, message); });
+    add_button(gpio, [topic, message](){ publish_message(topic, message); });
 }
 
 void set_status_led(uint32_t level) {