Hi Jim

As far as I am aware, this is currently not possible in Firefox.

Here is what I found, having been trying to find an answer myself a few months back:

Cast from laptop to Samsung TV To cast from your Windows 11 laptop to your Samsung Smart TV, ensure both devices are connected to the same Wi-Fi network, then press "Windows Key + P" and select "Connect to a wireless display." Choose your TV from the list, and follow any prompts to complete the connection.

Check Connectivity

1. Ensure both your Windows 11 laptop and Samsung Smart TV are connected to the same Wi-Fi network. 2. Confirm that your Samsung Smart TV supports screen sharing.

Using the Action Center

1. Open Action Center: WIN + "A" 2. Expand Options: Click 'Expand' to see more options. 3. Select Connect: Click on 'Connect' and choose your Samsung Smart TV from the list of available devices. 4. Allow Connection: If prompted, select 'Allow' on your TV.

Using the Project Menu

1. Open Project Menu: Press the Windows Key + P on your keyboard. 2. Select Connect to a Wireless Display: Choose this option from the menu. 3. Choose Your TV: Wait for your Samsung Smart TV to appear and click on it. 4. Enter PIN: If a PIN code appears on your TV, enter it on your laptop to complete the connection.