"To cast, give Chrome access in system settings." -- which system settings?

I recently upgraded my MacBook Air's MacOS and Chrome browser, and now I can't cast to my Chromecast device. When I try, I get the following message: "To cast, give Chrome access in system settings" - along with a helpful link to the Security and Privacy settings. For the life of me, I can't figure out which settings need to be set to allow casting. Search engine searches turn up one page, which helpfully describes this as "not an issue" with Chrome.

Details:

MacBook Air M1, 2020, 16GB RAM, OS Sequoia 15.0.1

Chrome is Version 129.0.6668.101 (Official Build) (arm64)

Chromecast adapter is third gen, firmware 1.56.291998

I have a work-around with my phone, but this is driving me nuts.