If you run into trouble opening the reset link, try the following...
It's possible that links are set to only open in a browser. To fix this, long tap the password reset link and then choose "Open with KOHO".
If the above doesn't work, uninstall and reinstall the KOHO app, then launch the app and request a new password reset email.
Give us a shout through in-app chat if you have any questions along the way!