Hello there,
Thank you for reaching us!
As you can see, the WordPress platform offers you the opportunity to have the website in the language you prefer.
What TranslatePress do? Our plugin selects a default language for your website and this is impossible to have 2 default languages (for example in TranslatePress you have English as default but you want to change from Settings-> General to have another language as default).
This won’t work because you can’t have 2 languages as default.
If you want to change the language of the Admin Dashboard, you can do this per user by going to Users-> Profile.
I hope everything is ok regarding this!
Let me know if there are any other questions!
Kind Regards,