When using the set with PC, just turn on the headphones and plug the USB dongle into the USB port of your PC, and they will auto pair to each other.
After they're paired, please check your PC sound settings and make sure the headphones are chosen as the audio input and output device on your PC as well as in the meeting software:
If you are using Windows system, please refer to the following pictures to check the Settings:
If you are using MacOS, please refer to the following pictures to check the Settings:
For meeting Apps like Skype or Zoom, please check within the app settings as well: