Actually there is nothing like highest paying programming language. It keeps on changing with time. In 2020 the top languages are:

1. Scala
2. Go by Google
3. Objective C
4. Kotlin
5. Ruby(on rails)
6. C#
7. Python
8. Java
9. Swift

People having command on these languages are highly paid. But as said things change with time and it's always good to keep yourself updated with new technologies and languages.