Hi @akshay7646,
Welcome to the Roku Community!
We're happy to help you with your problem casting your mobile phone on your Roku TV, as it no longer exists. The supported app must be installed on your mobile device and Roku TV to use casting. You must also connect your phone or tablet to the same wireless network as your Roku TV. Have you tried updating the software on your mobile phone and Roku TV? What model of the phone are you currently using?
Please check out this link on how to cast apps from your phone to a TV.
We look forward to hearing back from you soon.
Best Regards,
Eunice
Eunice L.
Roku Community Moderator