Please refer to the following on how to update each app type.
Web Browser
There is no need for a user to perform any update.
Mobile App (iOS)
Use the App Store to update iOS app:
https://apps.apple.com/jp/app/teachme-biz/id683050928
Mobile App (Android)
Use the Google Play Store to update Android app:
https://play.google.com/store/apps/details?id=jp.studist.teachme_biz