When you click on the button labelled "Export  World Generation Settings" a message pops up informing the user that the settings have been exported.

This message shows the full file path which can fill the whole screen if the .minecraft directory has a long path, but it should probably display the path relative to .minecraft (e.g. instead of "C:\Users\AGenericUser\AppData\Roaming\.minecraft\saves\genericworld\worldgen_settings_export.json", it should say "saves/genericworld/worldgen_settings_export.json").

Sorry if this is intended, but I think it's probably a mistake.