Is EF-SET English Certificate accepted?
The EF-SET English certificate is a test you take online without any supervision. From the EF-SET FAQ:

If the test is available to the public online, how is it secured from cheating?
Because it is intended as a learning tool, using the EF SET to its fullest advantage is the learner’s own responsibility. [...]. As an adaptive English test that covers multiple CEFR levels from beginner to advanced, the EF SET is designed to be useful to an individual as a measure of growth in proficiency over time and as a proxy to other expensive, high-stakes English tests like TOEFL, TOEIC or IELTS. To take advantage of this design, we advise that the test taker follow the timing guidelines and not try to cheat the test.

The homepage of EF-SET has three &quot;buttons&quot;:


Check your students
Evaluate your employees
Check your English


So the EF-SET test is intended either as a self-assessment tool, or as a tool that can be used by universities or companies to evaluate their students/employees, in which case the company or university will take care of the supervision.
If you come with an EF-SET certificate that you got by yourself, the institution has no way of knowing that it was really you who took the test. Therefore, it does not make much sense to accept this as proof of English knowledge. I have never seen this accepted at a university.