I have never heard of streaming a screen over bluetooth and I highly doubt that the bandwidth would be enough for even a few frames per second. Are you sure that your TVs bluetooth is for streaming a screen and not for audio only?

I'm not sure how you're casting over Bluetooth most TVs use WiFi direct

The official chrome browser has an option called "Cast" in their hamburger menu, chromium has it too if you can't bear to use Chrome but it's unstable

Gnomecast if you just want to stream video you've already got downloaded

If you're using it for gaming use the steam link/moonlight app on a Chromecast/raspberry pi/smartphone