Is the mic on the bottom left of your menu crossed out? If it is, click it to unmute yourself. Right-click the speaker in the bottom right of your screen, click Recording Devices, and ensure that the level on the microphone goes up when you talk. If you're running VRChat on PC, please try these steps. Install VRChat, and make sure to allow microphone access when starting the application. After doing that, uninstall the VRChat application completely and then reboot your device (hold the power button and power it off, then hold it again to power it back on).
If you're using VRChat for Oculus Quest, please first ensure that your microphone works in other applications. There are a few things that can prevent other users from hearing you correctly.
