How to fix missing minimize to tray feature in Thunderbird for Linux?

Question

Mozilla Thunderbird

It's an unsolvable mystery to me why the developers of TB stubbornly do not fasten the function of minimizing to tray! I wonder if this is for religious reasons, or is it, in principle, the most difficult task? After all, there is FireTray, but with each new version of TB, it is a contender for removal from the list of add-ons, because it is outdated. Well, they would have taken the engine from FireTray, and they would have screwed it to the main core of TB !!!

Actually, the convenience of FireTray is that it shows the icon for the presence of mail in the tray, and the number of unread letters. No need to periodically open TB and fumble through folders in search of new letters. No need to take up space in the taskbar for an open TB, just keep an eye on the tray icon.

Is it possible to make TB so that when you open it, you can immediately see all new letters in one place? Link type. Well, or something else.