@KMurumba If you are thinking about “custom translations” in the sense of type of language pack that you could apply to an existing instance, that is not something we support. (It is possible for you to rebuild your exact version with additional custom translations, but that would be a very complex process where you would have to fork the core plus all app repositories!)
Instead, we encourage users to contribute their translations to the community translation platform, and aim to get those in to later releases of supported versions of DHIS2.
We are just in the process of transitioning to the platform Matthieu linked above. We have only about a third of our apps there at the moment (I am on leave at the moment, but hope to get the rest in by early August).
By default translators contribute to the “master” version, which basically means the next release, currently being developed (e.g. v2.33 at the moment). We then port those translations to earlier supported version; the transifex platform greatly facilitates this process.
We will publish more detail about the process, including how to target specific versions, apps and languages, once we have the platform and workflow completely set up for all apps.
Kind regards,
Phil