Ultimately there does have to be an incision and an entry point for the cannula, so there will be some form of scarring.
For most patients though this is very minimal.
Given advances in technology as well, the size of the incision and the cannula itself gets smaller and smaller all the time, meaning less and less of a visible trace of the surgical process.
For most, any mark or scar is very small and fades with time.
If scarring is a major concern for you, ask your doctor during your screening to discuss the likelihood of scarring. Most doctors will be happy to show you the tools that would be used in the process and examples of their work in order to set your mind at ease.