ALL fighters walk in music must be chosen in advance and added to their profile form from the following tracks and played when the fighter walks into the ring.
Official Enfusion Theme + track 12 - 23 Produced by Mr Oasis (K. Ouaziz)
Music 2 - 11 24 - 33Produced by Dynamix recordings
Did you added your own Google API key? Look at the help.
Check in YouTube if the id PLwNaLxaoF87JgukMbNxTXj8ozhuvB8L3e belongs to a playlist. Check the FAQ of the plugin or send error messages to support.