Back in November, I pointed out the inability to launch actions from keyboard extensions in Drafts, but that's not true anymore as version 4.2.1 brings a new extension dedicated to run actions as keys. I'll revisit the action with Symbolay and you won't believe how easy it is to turn your actions into keyboard extensions.
In the aforementioned article, we developed a workflow to search for symbols and insert them in our Drafts document. The trick requires 2 actions: one to grab a search query – If any – and another for the callback. Download the actions below if you don't have them already.
You create a Run Action key as any other keyboard extension. Tap the pencil icon in the keyboard's extra row, tap the plus button in the top-right and choose Run Action from the dropdown menu. Fill the options, you may want something short for the label and for the Action Name use the name for the first action, Symbolay. Save afterwards and that's it. You can install this key directly here.