how to start particular desktop with startx

[Harry Putnam]

Setup:
Fresh install of ubuntu 20.04.1 in vm using vbox

1: I really want lubuntu desktop and not the defaults you get when
   installing ubuntu.

2: Also I really like to start in console mode and go to X using startx
   when needed.

3: (Most important) I want to have zfs on root which precludes
   installing from the lubuntu installer which makes no provision for
   installing zfs on root during install.

With thos 3 ends in mind.  I installed ubuntu using the zfs options.
I worked very well.

Once I had ubuntu with zfs going I installed the lubuntu-desktop

On boot, I had a chance to pick which desktop I wanted during login.

Ok, lubuntu is my desktop long as I boot to gui.

However I want to boot to console so made the necessary edits to
/etc/default/grub and set
   `systemctl set-default multi-user.target'

Booting to console works fine, however when I call `startx' it puts me
into the ubuntu default desktop but I want the lubuntu desktop.

And now the punch line
What can I put into ~/.xinitrc to allow startx to start lubuntu desktop?