Hey, Glad to see you join us.
Nikhil Install a spelling and grammar check on this site.
If you're talking about the red line that you see when there is a typo, then it does exist here in our text editor. Check the gif below to see how to toggle it.
Basically the default section of the editor is a preview section, you will have to click on the pen icon (the 3rd icon to the right of Post Reply/Post Discussion) to activate/deactivate it.