I am using CLion with Platform.io and everything related to Serial.print is logged into the Serial Monitor for me there.
Maybe you open the Serial Monitor after the Hello World is printed? If possible, try using “Upload and Monitor” so the whole process is immediately logged
We can’t say anything unless you show both code and platformio.ini.
It is an extremely common mistake for e.g. certain ESP32 boards to select the wrong board / settings, and then the Serial output suddenly goes nowhere (USB CDC vs UART).
void setup() {
Serial.begin(115200); // Initialize serial communication
}
void loop() {
Serial.println(“Hello, World!”); // Print “Hello, World!” to the Serial Monitor
delay(1000); // Wait for 1 second
}