Assign tags above 9 to message in Thunderbird

Are there any commands or functions in Thunderbird that assigns a specific tag to a message? I have more than nine tags, so I need more shortcuts.

I have installed the tbkeys add-on: https://github.com/wshanks/tbkeys
I’m able to assign commands and functions like func:AddTag and cmd:cmd_addTag, but those adds a brand new tag. I would like to use one of the tags I’ve already defined.

I would think that assigning a tag to a message is something needed much more often than adding a new tag, so it’s strange that I can’t find a way of doing it. I looked through the list here: https://hg.mozilla.org/comm-central/file/tip/mail/base/content/mainCommandSet.inc.xhtml
But the mailTagMenuItems only has addTag, mangeTags and removeTags.

Are there nothing like AssignTag(‘NameOfTag’)?