Using Ulysses and markdown for creation, can I import to publish?

I’m new to squarespace for blogging. Previously I’ve used Ulysses and markdown to create, format and the upload to WP to publish Since squarespace is not exactly a creation editor and can lose your work if you don’t save frequently, I was hoping to use an external editor for creation.

Most of my content is going to be long form.What are you bloggers using for creation? Is there a way to still use Ulysses?