How to add a synth with `dirt.soundLibrary.addSynth` and playInside

I'm trying to follow some examples in the superdirt hacks folder, but running into what seem like basic problems adding a superdirt synth.

Here's the example from /hacks/function-hacks.scd:

SynthDef(\plick, { |out, freq = 220, amp = 0.1, sustain = 1|
	var sig, env;
	env = EnvGen.ar(Env([0, amp, 0], [0.001, sustain]), doneAction:2);
	sig = SinOsc.ar(freq, LFNoise2.ar(XLine.kr(39, 300, sustain), Line.kr(15, 0, sustain)));
	Out.ar(out, sig * env);
}).add;

~dirt.soundLibrary.addSynth(\plack,
	(playInside: { |e|
		// make sure that you play it in the ~synthGroup and to the out
		(instrument: \plick, out: ~out, freq: ~freq, amp: ~amp, group: ~synthGroup).play
	})
)

When I run this and then try to play the sound via d1 $ s "plack" I get an error:

module 'sound': instrument not found: plack

So it seams I failed to add the synth, although there were no errors in SC when I evaluated the code above.

Generally I'm finding it pretty tough to grok the addSynth api, either via play or playInside. I can't seem to find a spec for dirt events that get passed around.

I recently followed the upgrade instructions so everything should be up to date.

Hi - I'm not sure how to resolve this, but I got a similar error, but only in SuperCollider, not Tidal.
When I run this, I get sound in one channel:
d2 $ s "plick*2" #freq "300 500"

So it shows that calling just the SynthDef works (using "plick" instead of "plack").

My suggestion is to read the Tidal Docs page on adding synthesizers:
https://tidalcycles.org/docs/configuration/adding_synthesizers

The dirt hack file says: "make sure that you play it in the ~synthGroup." I don't know what that is, but prepareSynthGroup is a method for the ~dirt object
~dirt.prepareSynthGroup(outerGroup)

I think group: ~synthGroup in the line below does this.