A translator is needed to translate an official letter into German.

I've a friend who work in a translation company. If you're interested I'll reach out him for you. His company Circle Translations-English to German translation is also cerified for the legal processes. There are differences in the dialect and language. Be aware about that too. https://circletranslations.com/blog/what-is-the-difference-between-a-language-and-a-dialect