Lora rylr998 to rotate one servo 90 deg

If a message is received, you won't know it unless the message contains a '\n' or new line, which is not sent by the posted transmit code.

    String received = loraSerial.readStringUntil('\n');

Avoid using Strings on Arduino, as they tend to cause program malfunctions and crashes due to poor memory management. This tutorial shows a much better approach: