You must update first to 2.16.3 - there is no other upgrade path. See the pre-flight check:
- Do you at least have Mautic 2.16.3 installed?
So you will need to do 2.16.0 → 2.16.3 and then you can upgrade to 3.x. Of course, ensuring that you have a backup that is tested, and ideally at the command line.