Scene Heading Style
Scene Headings are always printed in UPPERCASE. But some writers like them in BOLD as well, and/or UNDERLINED. Some writers like them with one blank line preceding them; others, two.
These choices are purely matters of personal preference, and although Slugline purposefully does not allow tinkering with the standard screenplay format, the appearance of Scene Headings so affects the feel (and page count) of your writing that Slugline does offer the ability to specify this one bit of cosmetics.
While editing your screenplay, tap the document name to access Document Settings. Here you'll find options for Scene Headings. You can toggle on or off Bold, Underlined, and Double Spaced.
These settings don't actually change the text of your Scene Headings in any way, only how they are displayed.