Once you've created your translation in either the Account Settings or Theme editor, you can select a translation for each specific form.
To select the translation, click Theme & Appearance → Translations → Edit Translations. The Theme & Appearance section is accessed in the top left corner of the editor.

In Translations, select the translation you wish to use.

Gotchas
- You can edit or delete your translation at any time.
- You can also opt to have any translation as the default for all of your forms.
- The ‘Submit’ button wording is unique to every form and can be set in the form editor via Theme & Appearance → UI Elements → Submit Button.