SDKMAN! does not distribute any Oracle JDK anymore. I think they stopped providing it for a while now(see their Medium article). I am used with the way of having multiple JDK versions managed by SDKMAN! and just switch between version using one command.
For my current project I have to use a certain Oracle JDK version, which is been installed locally on my machine, but I want to have it managed by SDKMAN!. Fortunately you can add your local JDK version by using the local install feature:
sdk install java 10-zulu /Library/Java/JavaVirtualMachines/zulu-10.jdk/Contents/Home
More info: SDKMAN! Local installation