Is it permissible to lift the niqab to record a "visual voice print" at the university, to avoid failing the course?

A woman must cover her face from non-mahram men. However, she is permitted to uncover it out of necessity, such as for identification purposes during travel, obtaining an ID card, or entering a university or taking an examination, if no woman is available to handle these matters. Similarly, she may uncover her face for photographs submitted for these purposes. What is forbidden as a preventative measure (sadd al-dhari'ah) is permitted out of necessity. Therefore, there is no harm in registering on a university platform with a visible biometric scan that requires uncovering the face, if no other method is allowed.