Review, then submit
Submitting runs your review commands, commits, pushes and opens a pull request. The
session moves to under-review and the board tracks the PR from there: its number, who
opened it, its labels, whether CI passed, whether it merges cleanly.

Merge the pull request in GitHub, as you would any other. Kosuke sees the merge through the webhook and closes the loop.
Everything above is also an API call. See the workflows for the same path in curl.