Changing the language on Netpass.

I accidentally clicked a few random inputs while trying to change the app’s language on my Japanese 3DS, and now I’m stuck. I even had to request the deletion of all my data. Netpass was always stuck on language 0 (which I assume is Japanese), yet I region-swapped the device three years ago... Once my save-data is purged, how would I set the language to 1?