Zero/Non-Zero Downtime Updates?

I am confused.
I have GitLab CE 11.11.0 running on my server.
I would like to update to the latest/current version - 12.3.0

Can I do it in one step following the “zero downtime” instructions ?
Or do I have to go 11.11 -> 12.0 -> 12.1 -> 12.2 -> 12.3 ?

Contrarywise, what are the steps for a non-zero downtime upgrade ?