How to set Join Before Host Setting

Initially, do the following (this is a onetime setting),

1. Go to settings and search for Allow participants to join before host in the search box.
2. Turn on the settling. Check the Participants can join check box and set the desired time by selecting it from the dropdown. (It's recommended to keep the time either 5 minutes before start time or 10 minutes before start time. Do not set it to anytime.)