I have a severe stutter (which speech therapy has never helped either). Whenever I go on interviews, I disclose upfront that I will require more time to speak, because of my stutter (the interviewer will find out soon enough if I don’t disclose, and it looks bad if I look like I “tried to hide it”). It’s no different than disclosing that you’re deaf before an interview, or that the interview must take place in an accessible location because you’re a wheelchair user.