I uploaded my Minecraft worlds from my iPad to iCloud and downloaded them to a PC, which all went fine. I then downloaded the worlds to a USB from the PC and plugged the USB into the PS4, but when I tried to upload the worlds to the PS4 it said there was no saved data and I am not sure what to do.
Ps4 encrypts its save files and requires them to have been encrypted via a PS4 to read them back, so sadly, you will not be able to transfer files directly from iPad/PC/Android.
You can transfer them via realms (though this will require you have PSplus on your psn account) now that PS4 finally supports them. Setup a Microsoft account and link it to the PS4 account you use (this is a one time operation so make sure you link the proper Microsoft account to the proper psn account). Buy a realm and then upload your save to your realm from your iPad using the same Microsoft account. You can then download the realm save on the PS4.
ascertain, you require to get an USB contrivance from Laptop or PC. So, it require from Laptop or PC. I suggest that, you require an USB contrivance to engage to get it, but, if you don't have any component Chargers that can insert Phone/other contrivances (not consoles, Consoles require USB) then you require to buy Charger part that is for USB as it able to insert contrivance (Phones, Pads, etc...) Withal, it's first time to indite English. but IF you have issue with it, please make contact to someone that whom is keenly intellective than me.
Have a good day.
Regardless - x Kushi