Email translations of welcome voucher module in PrestaShop

Good afternoon! How do I choose the language of the email that the "Voucher code after registration" sends? The language of the store is Portuguese, but does not appear in the translations section of the virtual store. 

Hello,

PrestaShop has feature that allows to personalize the emails that shop sends to customers.

This feature is available in shop by default. Depending on prestashop's version, you can find it here:

1. prestashop 1.6.x
   • log in to shop's back office
   • go to localization > translations
   • from first dropdown "Type of translation" select "Email templates translations"
   • from second dropdown "select your theme" select "core - no theme selected"
   • from last dropdown "select your language" select Portuguese (or any other language, if you want to change email for other languages too)
   • on the next page you will see the email templates that shop sends to customers, you can find there for template named "registervoucher": https://i.imgur.com/GsAflBk.png - and click on it
   • then click on "edit html version" - you will be able to alter the message contents: https://i.imgur.com/PtIpRwW.png 
   • if your shop sends email as a simple text - click also on "view/edit TXT version" where you can define simple text email contents: https://i.imgur.com/e4UT7DW.png 
   • title of an email can be altered on module configurataion page: https://i.imgur.com/ThJdASH.png 
2. prestashop 1.7.x
   • log in to shop's back office
   • go to international > translations
   • from first dropdown "Type of translation" select "Email translations"
   • from second dropdown "Select the type of email content" select "Body"
   • from third dropdown "select your theme" select "core - no theme selected"
   • from last dropdown "select your language" select Portuguese (or any other language, if you want to change email for other languages too)
   • on the next page you will see the email templates that shop sends to customers, you can find there for template named "registervoucher": https://i.imgur.com/zunaWUB.png - and click on it
   • then click on "edit html version" - you will be able to alter the message contents: https://i.imgur.com/05Mq5Q4.png
   • if your shop sends email as a simple text - click also on "view/edit TXT version" where you can define simple text email contents: https://i.imgur.com/R0ThOLn.png 
   • title of an email can be altered on module configurataion page: https://i.imgur.com/a38nrSX.png