Open the Sound settings in Windows 11 by right-clicking on the volume icon in the taskbar and selecting "Open Sound settings."
In the Sound settings, under the "Input"
geometry dash online section, locate the device corresponding to Line In 2 or the AXE I/O. Click on it to access its settings.
Look for an option related to channel configuration or mono/stereo settings. The availability and location of this setting may vary depending on your sound card or audio driver. Some common options to look for include "Channel Configuration," "Input Configuration," or "Recording Mode."