It’s not really that simple. As another commenter says, you have to disclose before you can formally request accommodation. And, given the disadvantages of doing so, it’s often not a good idea to disclose until there are problems. By that point, the employer might not be very cooperative, and, even if they are, the process of requesting accommodation need not be made easy or explained well. And, if things still go south despite disclosure and attempts to request accommodation, the options for dealing with that are limited. Basically, you can make an EEOC complaint, and that’s it. You will not win any friends by doing so, either.