Is AppEUI needed?

Is AppEUI needed?

Hi
I read the definition "The AppEUI is a global application ID in IEEE EUI64 address space that uniquely identifies the entity able to process the JoinReq frame." but I do not really understand it.
Im running the ST NUCLEO-WL55 Board with semtech LoRa library, LoRa version 1.0.3. The chip has its DevEUI from the chip manufacturer.
I also got the AppEUI 0101010101010101.
Who defines the AppEUI? The chip manufacturer? Or should the AppEUI be defined by end device manufacturer (not by chip manufacturer) and run own join server?
I tried to change the AppEUI to a random number and the end device successfully connected to ThingPark Actility server.
The LoRa server (ThingPark) knows the DevEUI and the AppKey, so is AppEUI needed?
Thanks for answer
Tomas