The hard part is proving it. They’ll say it’s culture fit, or there’s a more qualified candidate. Being fired for any reason other than the real reason gives them indemnification should you say otherwise.
I’ve had exactly one job where I mentioned having a disability to HR and also one job where I got summarily fired for no apparent reason.
Keep your mouth shut about disabilities, and edit your resume so you look to be age 25-30. For interviews etc style yourself so you don’t look “old”.
Well, I have some stuff in writing that shows they violated the ADA at least twice. So a lawyer should be able to get a nice payout for me when they do fire me.