Renpy is not unity, and its operation is very different
Renpy has tools to export texts to files that can be translated, the problem is that the ID of each line is generated as a hash of the original text.
If you try to create the translation in the middle of creating the game, you often run into problems with IDs, which means having to repeat a lot of work.
On the other hand, if you do it when the game is finished, you will save yourself a lot of headaches.