Try one of the few methods:
1. Bit down on the mouthpiece fully and keep lips sealed so that no air escapes from the sides.
2. If you're experiencing coughing, try taking a break and drinking some water to clear your throat.
3. Make sure your tongue is out of the way and not inside the mouthpiece.
If you're still having issues after giving this a try, please reach out to us at firstname.lastname@example.org and we'll help get things back on track.