In VRChat audio settings you can't select the Voicemod Virtual microphone and you only have the option to get the default system microphone, you have to set Voicemod Virtual microphone as your default system microphone:
- Go to Control Panel > Sound > Recording Tab
- Select the Microphone Voicemod Virtual Audio Device and set it as the Default device
- Apply the changes and it is done.
Now you can go again to your VRChat and select the default device as your audio input.
*Do not use the Voicemod Virtual Audio device as the output (headphones), we need it internally as an audio bridge to make all this work.
Through this output, you will hear the transformed voice if Voicemod is opened, but not the rest of the sounds coming from games or other applications.