AL Extension for Runtime 5.0
If you want to do some testing with BC 2020 Wave 1 Preview, you will need to have AL extension version 5.0. However, the AL version 5.0 is not available yet for public.
If you have a BC 2020 Wave 1 Preview container, you can get the AL 5.0 extension by using the following URL in your browser (replace yourcontinername with your own container name):
http://yourcontainername:8080/ALLanguage.vsix
You can then import it manually to your VSCode. Once installed, you just need to reload your VSCode and you should be good to go.