If you legally own a digital copy of Jujutsu Kaisen (e.g., purchased from iTunes or Google Play) and wish to compress it to x265 for personal storage on a Plex server, that is permissible under in some jurisdictions (check local laws). Tools like HandBrake (free, open-source) can convert your legal files.
Upon initial inspection, the file name suggests a video file, possibly a movie or anime, with a mix of English and Japanese characters. The filename "vegamoviestojujutsukaisens021080px265" can be broken down into parts that may indicate: vegamoviestojujutsukaisens021080px265
x265 – Video codec: HEVC / H.265, which provides better compression than H.264, often used to reduce file size while retaining quality. If you legally own a digital copy of Jujutsu Kaisen (e