@Gayan6 Click on the Booking Settings tab on the Listing editor. Under Guest Requirements, select "Profile Photo" to activate the requirement that all guests have a profile photo in order to submit a request.
However, that setting doesn't account for the fact that the photo might not be a picture of the guest - it might turn out to be something stupid, like a pink flower.
Airbnb does not require profiles to have a photo, so the absence of one is not in and of itself indicative of a scam. But as long as you're not using Instant Book, you can screen your guests with some correspondence before accepting a request. You can also require in your House Rules that guests present a photo ID at check-in in order to access the property, if you're concerned about fraud.