Go to installations and press "new".
Now, go to version and click "latest snapshot" or any of the snapshots you want.
Give it a name or don't, doesn't matter.
Click create and then go to the "play" tab.
Next to the play button, there should be a drop down menu. Click it, then click the name you gave the snapshot.
Click play, wait for it to download, and be free!
Note that I do not know if there is any differences between windows java and macOS java as I use windows.
Hope this helps!