3.3 ここだけ押さえれば開発は進められそう! dependencies { implementation("androidx.core:core-ktx:1.10.1") api("androidx.core:core-ktx:1.10.1") } implementationとapiの違いはこちら! https://docs.gradle.org/current/userguide/java_library_plugin.html#:~:text=jav a%2Dlibrary%60%0A%7D-,API%20and%20implementation%20separation,-The%2 0key%20difference