Whether or not OneKeyVisda is "legit" is not a legal question. The law as it pertains to visas is. This is the applicable regulation. The applicant must be "accepted for attendance for the purpose of pursuing a full course of study" etc, and
(iii) The alien, unless coming to participate exclusively in an
English language training program, has sufficient knowledge of the
English language to undertake the chosen course of study or training.
If the alien's knowledge of English is inadequate, the consular
officer may nevertheless find the alien so classifiable if the
accepting institution offers English language training, and has
accepted the alien expressly for a full course of study (or part-time
course of study for Border Commuter Students) in a language with which
the alien is familiar, or will enroll the alien in a combination of
courses and English instruction which will constitute a full course of
study if required
The law does not require specific test scores, it requires sufficient knowledge of English. It is the responsibility of the university to set the standards. If the language of education is English, then knowledge of language may be assumed: or not, depending on university policy. My university had variable standards in that respect over 30 years.