I was given a doctors note stating I can not wear a face mask, but my work said that since the doctor's note doesn't state why I can't wear one it's not a approved reason.
Under the Americans with Disabilities Act, your employer is obligated to engage in an interactive process with you to come up with a reasonable accommodation for a disability. If your employer has additional questions about what your disability is and how it restricts your ability to wear a mask to determine whether your request not to wear a mask is reasonable, they are allowed to ask these additional questions in order to come up with a solution that will work both for you and for the company.