Have you tried?
Otherwise, if by "cast" you mean screen mirror (using Miracast), then you wont be able to do so until you root your phone and make some modifications:
https://techlector.com/how-to-connect-google-pixel-3a-pixel-3a-xl-to-tv/
https://howtotechnaija.com/connect-google-pixel-3-and-pixel-3-xl-to-tv/
(You can thank Google for disabling/hiding the industry-standard Miracast functionality in its later Android versions and devices in favor of its proprietary-and-incompatible-with-Miracast Chromecast functionality...)
