Reverse Information.mp3 from this site : https://mp3cut.net/reverse-audio Now listen reversed audio and you will get some clue

Listen second audio: Message.wav This sounds like morse code You will get decoded text by uploading this file (Message.wav) into https://morsecode.world/international/decoder/audio-decoder-adaptive.html

Decoded text from morse code: 7U2QU01535011741230F4242841J4N

flag:

UCTF{7U2QU01535011741230F4242841J4N}