New IntroServer for PES 2021 made by Forever Milan. K-League isn’t available in PES 2021.
Preview : https://www.youtube.com/watch?v=iBi6PZmZMpc
1. Install IntroServer.lua
2. Extract file with WinRAR and copy all .usm files to
livecpkintroservermovieintro
3. Open IntroServer.lua and read the instruction how to add custom intro ( i recommend notepad++ to open IntroServer.lua
3a. To see Tournament IDs, go to doctournament.txt inside sider folder