Go to this site
https://adoptopenjdk.net/?variant=openjdk11&jvmVariant=hotspot
and choose OpenJDK 11 LTS and HotSpot JVM.
Execute the .msi installer and you are done. To check if it worked open a command prompt and enter
java -version
The result should be
openjdk version "11.0.7" 2020-04-14
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.7+10)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.7+10, mixed mode)
