So, you're writing a blog that can't fit into just one category... Luckily, we have the feature of adding multiple categories to each article!
After typing up a new blog post, click on the gear icon in the top right of your Unstack editor to access the settings drawer.
Once you have clicked on the gear icon to access the settings drawer, open the dropdown under "Categories" and select your first category.
To add a second category, repeat this process. You'll know that you've done this correctly if you see both categories side by side, see my example below for reference.
Make sure to save and publish your changes to make sure these are updated on the live site of your blog post.
Congratulations, you've successfully added your blog post to multiple categories!