I have an entrerprise plan: Adobe Pro for Teams. But, I still can't choose the email's language when I request a signature. I don't have that option, like if I had an individual plan (which it's not this case).
You said you have Acrobat Pro for Teams. If that is true, you cannot have an enterprise plan. The email's language can only be changed s using Acrobat Sign for Business or Acrobat Sign for Enterprise. They are completely different products.