asking work for accommodations

I work on a unit where we are supposed to do “rotation” for shifts. Either you work days/evenings, evenings/nights, days/nights. Day shift is the most popular, so if someone wanted to only work evenings or only work nights, it would be allowed. I work days/evenings and up until now I’ve been getting away with doing very few evenings. dLately they’ve started scheduling me almost 50% evenings.

My issue is that I have an autoimmune disorder, my worst and continuous symptom is extreme fatigue. When I work evenings I struggle—I’m exhausted, I can’t sleep, I honestly feel unsafe at work. I’m seeing my doctor soon and I’m going to ask for a note that says I can’t work evenings…

Has anyone needed a similar accommodation? If so how was it worded? And how was it received by your manager?