Why I got this msg when I am trading option?

You are trying to use a market order for stock options which is no longer supported.

https://fyers.in/notice-board/changes-in-options-trading-w-e-f-18th-october-2021/3

Hey @Mohamed Ali5,

Your F&O segment isn't activated. Thus, your order is getting rejected. I have reverted to you in DM. Kindly check your inbox. We can take it forward from there. 

Thanks!