What actually helps in a job interview?

I have had four interviews this year and the accommodation conversation goes differently every time.

Twice it was fine. Once the recruiter got visibly flustered and rushed the rest of the call. Once they simply did not book the interpreter despite confirming it in writing.

For those of you further along: do you raise it before the interview or at the start of it? I keep changing my approach and I am not sure which is better.