This is one of my most used Shortcuts now I have removed posting friction and settled a little. Shortcuts is a really robust way to publish to WordPress and not have to use the WordPress app or third party app.
This isn’t all of my work, and all the technical stuff was done by Tim Nahumck in his drafts review it just needed updating and tweaking a little as Shortcuts evolves.
You can write a post in pretty much any app you have now. Use Markdown format though as the shortcut looks for # to set the title and removes all this for you. See my screen shots for an example of my Apple Notes publishing.