Translation Package distribution
You can go to the Downloads website and login: https://downloads.joomla.org/#
There you could go to the Joomla 4 branch of the download site: https://downloads.joomla.org/language-packs/translations-joomla4
You will find the language you manage as one of the many visible, with a “Create a new release” button, next to the “Download Language Pack” button.
On the “Create a release” page within your language it’s possible to enter the version (E.g. 4.0.0-rc1), select the language pack version 1 if this is the first upload for the Joomla version (E.g. 4.0.0-rc1), and so on.
Press "Submit" to finalize the upload.