First pull latest develop and do a bin/doom update
in your .emacs.d
navigate to this file and comment these lines:
https://github.com/hlissner/doom-emacs/blob/develop/modules/tools/lsp/config.el#L50-L57
change this line: https://github.com/hlissner/doom-emacs/blob/develop/modules/tools/lsp/config.el#L3 to read company-capf instead of company-lsp
type /**
above a class or whatever which will autocomplete a blank template, then use M-x
and
type company-capf
you should get a popup for scaladoc completion