Just as every job and employer is different, so too are the ways of disclosing your disability. At the time of application 1.2. On your resum 1.3. In your cover letter It would be nice to say that all that employers are concerned about is whether the person applying can do the job. Unfortunately, this is not strictly true.
Employers are human too.
They all have likes and dislikes, prejudices and fears. Many are ignorant of the fact that persons with disabilities have abilities and skills that are as good as, or better than, the rest of the population, skills that could contribute to the success of a business or company. Application forms may include a question asking you to identify anything that might impair your ability to carry out the duties of the job successfully. Whatever you do, don't lie. Lies have a way of coming back to haunt you.