I found a script online with a weakaura, but it makes global variables. Sometimes it also shows the wrong keybinds
#I need to make a script that makes the weakaura show the spells keybind automatically.
shut delta
modern hinge
That's not easily possible.
Finding which spell is bound to which key is a hassle in the first place and needs slightly different handling depending on the Actionbar Add-on.
And then you gotta keep in mind that no weakaura corresponds to a keybind naturally.
You can grab the WAs data and check what it tracks via triggers, but drawing the correct conclusions from that can also be a hassle. And depending on how your WAs are set up: potentially lead to false positives.
There are a bunch of WAs around that do what you ask for (with more or less unnecessarily bad performance).
If none of them are to your satisfaction, then you're on your own.
twin tulip
if you want to look at the code of some Addons that identify that sort of thing (e.g. hekili for its predictive rotations) you might find the lua scraps that do it.
I have no info about performance issues
modern hinge
You can look at Hekili for getting the Keybinds yes.
But matching that to certain WAs is still something you gotta figure out yourself.
More or less unnecessarily bad performance
Was referring to certain WAs that already do this. As in: matching keybinds to a WA and also providing an overlay for button feedback.
They call WeakAuras.GetData too often, they create frames that aren't managed by WA (and then don't manage them well themselves), their implementation of the button press feedback is sometimes faulty, etc.
Not all of it, but some of it in each such WA I've seen.