Where is the zita-at1 plugin?

[tramp]

Under which name is it? Under which plugin group, or which plugin deveroper name?

here you go:
https://github.com/x42/fat1.lv2

[tramp]

If you talk about Zita-AT1, then it should be this one.
Properly you've installed it with the X42 plugin package from KxStudio, and you'll find it under By Creator->X42->Autotune

[sysrqer]

I don't think it is a plugin, as far as I understand this was why x42 forked it, to make it a plugin.

[sysrqer]

Installed the x42 plugins ....

And?

[sysrqer]

In that picture you are hovering over a button, are you expecting to see it there?
Open the plug in manager and look for it, or look under Creator> (don't remember the name he shows as, might be Robin...).

This plug is does exactly what you are wanting it to do.

[sysrqer]

The x42 one is a plugin. Show a screen shot of what you have when you go to creator, robin.
What did you install exactly and where from?
I would also recommend reading this thread again, the jack Vs plugin situation has been explained a few tones already.

[sysrqer]

That's a very old package and doesn't have the plugin you need.
http://x42-plugins.com/x42/x42-autotune