There is a folder /languages/ in the /leaguemanager/ plugin folder, where you can find the translation files. You can edit or create a file for your language with something like Poedit (https://poedit.net) to fit your needs.
You can also contribute to the official translation of the plugin: https://translate.ww.wp.xz.cn/projects/wp-plugins/leaguemanager
in leaguemanager/folder i have only:
-templates
-css
-lib
-admin
-sports
no language folder
I don’t know what to say. I just downloaded the current file from wordpress, and it contains a language folder. Are you sure you have the right files?
It contains translations for French, Polish, Spanish, German, Netherlands, Italian and a a couple more.
