change of permalink

hello support!
i need to change this “https://demo.upupapavliani.gr/index.php/premium_apartment_loft/”
to this “https://demo.upupapavliani.gr/accomodation/premium_apartment_loft/”

I tried installing Permalink Manager Lite widget to do so but it would say that this url is not found in the sever.
Can you please login and let me know?

I would like to remove the “index.php” from all page urls please.