Can I use mobile hotspot for smart tv

If I understand your question correctly, you would like to connect your SmartTV, via WiFi, to your iPhone/iPad hotspot.

Provided that your subscribed Cellular plan supports hotspot connections (some Cellular Carriers may charge an additional fee - or may not allow hotspot connections), then there is no technical reason why you should not be able to connect to your iPhone/iPad hotspot.

You will need to manually enable the Personal Hotspot:

Settings > Mobile Data > Personal Hotspot > Allow Others to Join - set to OFF

NB: Make a note of the Wi-Fi Password.

From your SmartTV controls, you will need to connect to your WiFi Hotspot - using the Wi-Fi Password that you have obtained from your device.

Be aware that your SmartTV will consume a lot of data when streaming video - which, over a Cellular hotspot, may be very expensive!

How to set up a Personal Hotspot on your iPhone or iPad – Apple Support

Have you tried it?

Does your smart TV use Apple AirPlay 2 technology.

What make of smart TV do you own?