The anser is "A": Teams devices -> Panels -> Configuration Profiles -> Toogle: Maximum room occupancy notification (ON)

C: Enable or disable room capacity warnings Teams panels that are paired with Teams Rooms on Android can display a warning message when a room is at or over capacity. To use this feature, Teams Rooms must have a camera that supports people counting. Teams Rooms on Android support room capacity warnings without a Teams panel. Note Room capacity warnings aren't available in the GCC-High environment. Room capacity warnings are disabled by default, but they can be enabled per device. To enable the feature, do the following: Follow the steps in Pair a Teams panel with Microsoft Teams Rooms on Android. The panel and the Teams Rooms device must be signed into the same resource account. Go to Settings > Device settings > Teams admin settings > Meetings and turn on Max room occupancy notification. Enable or disable