Check out example codes for "bungeecord plugin add configs". It will help you in understanding the concepts better.
Code Example 1
// Load config
Configuration config = ConfigurationProvider.getProvider(YamlConfiguration.class).load(new File(getDataFolder(), "config.yml"));
// Sets a string
config.set('test', 'This is a test');
// Loads a string
config.getString('test'); // test
// Save config
ConfigurationProvider.getProvider(YamlConfiguration.class).save(config, new File(getDataFolder(), "config.yml"));
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