Basically find the code for the language you are seeking to translate further. If it is a new language then I’m not sure the exact steps but most likely you just add the LANG_CODE directory and create an airtime.po
I’m not 100% sure if there is an additional step you need to do afterwards.
Were you able to get the install working ? If so I’ll have to open up a bug for the installer to fix the issue with special characters.