It seems that many people have asked how to get the top bar on multi-monitors for Ubuntu 18.04 (e.g., Ubuntu 18.04: Top bar for all monitors, Ubuntu 18.04 Gnome bar on all monitors). There is no satisfactory answer there. I'd like to know if a solution exists for Ubuntu 20.04?
EDIT: I've already tried the Mutli Monitors Add-On but it doesn't work properly for me. I'm not able to get sounds parameters on both top bars and there are problems with some indicators.