Where can I find option buttons for I IR R with the melody

Hi, I’am a composer. I have bought Dorico Pro 3.5. I want to find the otion buttons for inversion or retrograde and also retrograde inversion a melody.
These functions can be easily found in the software I used before,like Avid sibelius.
Thanks for you read my letter . I’m looking forward your reply.

Welcome to the forum, and to Dorico! Unfortunately Dorico doesn’t yet have in-built retrograde or inversion features. It’s on the list for sometime in the future, though.