Well first thing first, you may want to completely finish the game first because the translation will copy the script and code to make the new language version. Also make the button for the new language, Renpy won't make it and if you have imagebuttons, this may cause errors. Lastly any error in the game even a small one will stop the process until it is fixed.
Now that you know what you need to do first here is how to make one:
- Open Ren’Py launcher and select “Generate Translations"
- Type the language for the game
- Check "Generate empty strings for translations" this will make the character's speech into nothing in the new language version.
- translation files will be placed under thenameofgame/game/tl/United Kingdom (note United Kingdom is an example not a langrage)
- The new translation version will be in the new folder that Renpy made so you go and click tl and then United Kingdom
- Find the script.rpy inside United Kingdom folder to edit it.
- This is what you will see: https://imgur.com/a/MtKKUMQ
- Write new text in the blank character speech, do not do anything else unless...
- If you encounter an error with the translation code tags, meaning if start_1111 exist and another start_1111 exist in another character's speech, you will need to edit those tags so it becomes start_1111_2. This is rare but may happen so test the game to be sure.
- As for image, you add it into the United Kingdom folder so you will click on nameofgame/tl/United Kingdom /picture.png (this is where you place it, renpy already has the code ready so you do need to add extra image into the game if you have any). This also goes with nameofgame/tl/United Kingdom /gallery/picture.png if you have translated extra modes like gallery, music, profiles, etc. If the code isnt from renpy then extra mode may not work and may need to be worked on to work on United Kingdom.
That is everything i know on how to translate the game, it's hard and long but works way easier considering you wont have to retype new code, just translate any image and text, simple.