A caregiver of a child under 4 years old can acquire such a ticket via KOLEO. To do that one needs to visit the bookmark “PASSENGERS” https://koleo.pl/profile/passengers and input the data set referring to every Passenger. The first letter of each person’s name and the first letter of that person surname will be visible on an icon representing said person (so for a person named John Doe the icon representing that person will have letters “JD” on it). You will be able to add and remove that person from and to the default Passenger set by simply clicking on such an icon.
There is also one more possibility – simply use the “FIND YOUR CONNECTION” button on the https://koleo.pl/en/ after imputing the departure and destination stations and also choosing the date and preferred time of departure. Afterwards you will be presented with the list of possible connections and when you’ll point the cursor on the price regarding to a specific connection then the price will be replaced by the button “Buy a ticket”. Press that button to proceed and then you will be presented with the default set of Passengers. It will however be possible to add, remove and even create new entries.