Regulation (EC) No 1107/2006 of the European Parliament and of the Council of 5 July 2006 concerning the rights of disabled persons and persons with reduced mobility when travelling by air
In addition to medical equipment, transport of up to two pieces of mobility equipment per disabled person or person with reduced mobility, including electric wheelchairs (subject to advance warning of 48 hours and to possible limitations of space on board the aircraft, and subject to the application of relevant legislation concerning dangerous goods).
On Wheelchair Air Travel: Tips And Tricks To Get It Right it notes:
European legislation applies to all flights departing from any airport inside the European Union, and to incoming flights operated by European airlines only.
The biggest challenge will be security. There are two things you must do: one is to contact the airline at least 48 hours prior even if you don't use an electronic wheelchair becaues this will allow them to arrange assistance at the airport. Ask them specifically to do so. Also, arrive early to the airport, two hours is strongly recommended. Some airports will get you through a special security lane, for example the Prague airport clearly has this. EnterAir uses Warsaw airport, the relevant page asks you to use the intercoms when there and this PDF says:
The scope of assistance available at Chopin Airport ...
help and assistance during ... security screening before departure;
When browsing this PDF you can also find service standards and that it takes 15 minutes longer to get assistance if you are not pre-booked. Even if pre-booked, they state in the worst case you might need to wait for 30 minutes for assistance. This is why you should be early.