Once a meeting has been started, the Roll Call cycle can begin, and to do that you should click the green Roll Call button:
When you start the roll call process, members' screens display a blue Present button:
When they click their Present button, they are shown as present on your screen by the blue P button at the beginning of each member's layout row:
The blue P button is active on your screen, meaning that you can also click it to make a member absent, if you need to for any reason. At the end of a member's row, a status indicator also shows that this member is present. In other stages of a meeting, this status indicator may change to say "Voting" or "Vote Locked", but the blue P button always reflects a member's present or absent status.
When every voting member who is in attendance has established their presence, click the green Tally button to "count noses" and establish for the record how many members are present and absent. The roll call tally - as well as other vote tallies - is shown at the bottom of your screen under the member name grid and a green Quorum Present message displays to the left of the tally:
At the same time, if you are recording results, the present/absent status of each voting member and the roll call tally is written into the meeting's Results document.