There are a couple ways to join your meeting on the Biba app.
The easiest is to be signed into your account on at lease one device, and at least one minute before the meeting is scheduled to start.
At the meeting start time, you will receive a call notification, allowing you to answer, choose your audio, and you're on the call.
If you didn't get to your device in time for the call notification, don't worry - as long as the call is still active, you can still join.
From the Home screen on Desktop, select Join Meeting. A screen showing any meetings you have starting in the next 30 minutes will pop up, just select your meeting from the list and click join.
From this same screen, you can also choose join by PIN, add the organizers PIN, and join the call that way. This can be especially helpful if the call organizer didn't invite firstname.lastname@example.org or even attendees to the meeting, and just sent out dial-in info.
On mobile, select the Meetings tab, and follow the same steps.