You can now turn the coffee maker on. There may or may not be an indicator light that illuminates to tell you it is on. Either way, you will tell in a minute or two whether it has turned on or not by the noise of it starting to boil the water.
When the coffee machine is finished, it should automatically turn to ‘keep warm’* mode. This will keep the coffee at the optimal temperature. If you do not want it to keep warm then you can simply turn the coffee machine off.
If you like your coffee ready for you when you wake up in the morning, why not turn your standard non-smart coffee machine into a smart coffee maker?
*Note that manufacturers usually recommend not keeping the coffee machine on keep warm mode for more than a few hours, ideally no more than two hours.