Copy the InVision prototype "share link" from InVisionapp.com. The share link is located in the upper right corner of the prototype.
Learn more in InVision's Help Section.
You will be asked for a Landing Page to send participants to. This is where you can paste your InVision share link:
That's it! From here, when you send participants a Participant Link, they'll be redirected to the InVision prototype on their device.