The PSR-E363 doesn't have a USB TO DEVICE port for plugging in a USB thumb drive, so the external style file(s) would need to be transferred into the keyboard's internal storage memory from a connected computer using Yamaha's MusicSoft utility.
I think there are only two such utilities available, unless Yamaha has added more versions-- the Yamaha MusicSoft Downloader program for Windows, and the Yamaha MusicSoft Manager app for iPadOS or iPhoneOS. As far as I know, there is no version for the macOS.
