Purchasing PC and PS4 versions

[Sotaris]

So I just ordered the Endwalker expansion and added it to my account. Will I have to also order the expansion for the PS4 as well if I want to play on my ps4 or is buying the PC version all that I need?

Yes. I play on PC and PS5 and play primary PC so only got it on steam now and will get it on PS5 later on.