SP Page Builder is multilingual-friendly and can be translated easily. You can install translation of the component from the extension itself. Language packages were created by the community. We use the transifex platform to manage SP Page Builder translations. Example tip on how to translate Contact Form you can find here.

To do that, go to SP Page Builder Dashboard>Languages. 

From the list, select your preferred language and install it. 

Before you can translate your SP Page Builder into a new language, you need a working multilingual website that has that language as the default language - read tips on how to set/create a multilingual site in Joomla 3 or Joomla 4.