Thanks for visiting the Community.
To confirm, are you trying to connect your TV with a built-in Chromecast to your mobile hotspot? If yes, you will need two mobile devices for this setup (one will serve as a router and the other to be used to set up your TV with built-in Chromecast). Please note that we do not recommend connecting your device to a mobile hotspot because your TV needs a strong and stable internet connection.
Hope this helps.
Just bumping in to make sure that you've seen our responses. I'll lock this thread if we won't hear from you in 24 hours. Feel free to create a new one if you have more questions or have other concerns in the future.