This tutorial has an issue which uses Handler, but this method is deprecated. Please fix this particular issue by rewriting the tutorial. There was already an issue in it showing findViewById, which is another deprecated method, but the rest of the tutorial uses View Binds.
This is a paid tutorial so it is more important to fix those issues
Course: https://www.educative.io/courses/modern-android-app-development-kotlin
Lesson: https://www.educative.io/courses/modern-android-app-development-kotlin/B1k2QBw3nYW