Recently Google added 24 new languages.
This is the full list:
Assamese, Aymara, Bambara, Bhojpuri, Dhivehi, Dogri, Ewe, Guarani, Ilocano, Konkani, Krio, Kurdish (Sorani), Lingala, Luganda, Maithili, Meiteilon (Manipuri), Mizo, Oromo, Quechua, Sanskrit, Sepedi, Tigrinya, Tsonga, and Twi.
You can see this article[1] about that.
[1]https://www.gsmarena.com/google_translate_gets_support_for_24_additional_languages-news-54274.php
These are the new 24 languages[1].
In that post there is a research paper[2] where you can see the codes it begins on page 57.
Currently the documentation it is in an internal Work in Progress with no launch date yet.
[1]https://blog.google/products/translate/24-new-languages/
[2]https://arxiv.org/pdf/2205.03983.pdf