The option 'android.enableR8' is deprecated and should not be used anymore. It will be removed in a future version of the Android Gradle plugin, and will no longer allow you to disable R8.

Questions & Answers
1

The option ‘android.enableR8’ is deprecated and should not be used anymore.
It will be removed in a future version of the Android Gradle plugin, and will no longer allow you to disable R8.

how to fix this on unity version 2020.3.19 lts

2

i have the same problem, can’t find a solution using google