Thank you for your reply. I will be more thorough in my discussion.
2017 macOS Sierra 10.12.6
AirPlay icon in the top bar; "AirPlay Display" toggle in the System Preferences Displays control panel; mirroring options checkbox in the System Preferences Display control panel.
2022 Samsung Crystal UHD 7 series TU 700D TV
AirPlay enabled in systems general menu
Apple information says this TV is compatible with AirPlay
Starlink; wireless network identical in both devices; Mozilla Firefox browser 115.7.0esr (64-bit)
With both devices turned on, with both devices connected to the same network, when the AirPlay icon on the Mac is activated, the message toggles between "Looking for Apple TV" and "Off", but does not locate the TV although they are within 10' of each other. The System Preferences Displays control panel's "AirPlay Display" selection toggle has no other choice but "Off" although there is a toggle switch. The checkbox for "Show mirroring options in the menu bar when available" is checked, but I have not located a mirroring icon.
I am attempting to cast the Met Opera "Live at Home" live stream from the Mac to the Samsung. In their Technical Requirement discussion the Met Opera states: cast the performances to your smart TV from your desktop computer using Chromecast or AirPlay. . . . We do not recommend trying to access the links in a connected/smart TV.
If there is any other information necessary please do let me know. Thank you very much!