Despite various laws etc, don't mention your age on your resume, and only list a few previous roles (perhaps the last 5-8 years max with "more details available on request" or something vague). Don't put your graduation date etc. Don't list job history going back decades. Basically don't give people any ammo to think you are "old".

Bias - unconscious or otherwise - is real. It sucks but you may need to try to work around it and play the games. Don't lie, just don't mention it or bring it up.

Good luck.