The easiest way to add a new text layer to your design is to click on a Column or Hero layer, and then select the Text option from from the Quick Add dropdown menu, and then click the Add + button to insert a new text layer to your design.

You can also drag and drop (or copy and paste) any existing text Figma text layers on your page into any Column or Hero layer as well, and these will be rendered as rich text in your emails, too.

If you need to, you can swap the default paragraph tag (p) for any heading tag (eg., h1, h2). You can wrap your Figma text layer content with a heading tag you're after, and that will automatically handle changing the tag when the HTML is exported via the Emailify plugin.