> Of the, say, 10 branches you've got checked out, how do you know which branch maps to jira-123 and which one maps to jira-234, or if you're using names, which anonymous branch maps to addFeatureA or fixBugB?

The descriptions of the changes. I shared some jj log output in another comment, here it is with more realistic messages, taken from a project of mine:

    @  vvxvznow 
    │  (empty) (no description set)
    │ ○  uuowqquz 
    ├─╯  Fix compiler panic in error rendering for anonymous struct methods (rue-fwi9)
    │ ○  uvlpytpm 
    ├─╯  Stabilize anonymous struct methods feature
    ◆  lwywpyls trunk
    │  Fix array return type unification in type inference

> Specifically, there's a jira cli (well, multiple) as well as a gh cli for github as well as gitlab has one as well.

These systems do require branches in order to open a pull request. In these cases, I use `jj git push -c <change id>`, which will create a branch name for me, and push it up. This is configured to produce a branch name like steveklabnik/push-mrzwmwmvkowx for a change with the id mrzwmwmv, and ultimately, it's still easier to name locally with m or mr depending on if the prefix is ambiguous. That said, from there I do usually just click the button and then "open pull request" on GitHub, but like, all of these tools (gh is the only one I've used, but I can't imagine that the others do not work, since ultimately, it's a git repo) just work if you want to use them.

Other systems do not even require a branch to submit, and so you don't even need to do this. I would say "submit mr" and it would return me the URL for the created change request. Gerrit does this on top of plain old git.

> how does it get the ticket name to submit the code to the system under?

I haven't worked with Jira in a long time, but with GitHub, if I make a change that fixes issue 5, I put "Fixes #5" in my description, and when the PR is created, it updates ticket #5 to link the PR to that change automatically, no other process needed.