You can input ornaments, trills, and jazz ornaments using the ornaments popover, both during note input and by adding them to existing notes. When inputting trills, you can specify the trill interval, such as a minor third.
Procedure
Result
During note input, ornaments are input at the caret position. Trills last the duration of the rhythmic value of the note input at the caret position or the duration by which the caret advanced. Trills have a default interval of a second, either major or minor depending on the context. If you specified an interval for your trill, the interval applies only to the first note in the selection, but you can also change the interval partway through trills.
When adding ornaments to existing music, they are input at the rhythmic position of the earliest selected item. Trills are input at the rhythmic position of the earliest selected item, with an extender line across the rest of the selection.