The number to be dialed can either be taken from the contacts or entered manually.

If the caller answers, the following options are available:

A DTMF signal can be sent via the dial buttons.
(e.g. for hotlines with a selection menu)
The call can be ended via the “Hang up” symbol.

Another caller can be added to a conference using the icons at the bottom.
You can switch off your own microphone using the “Loudspeaker” symbol