It's really bad experience of my life when I bought Nokia 3 , it's have no screen mirroring casting options. If u buy any 3rd class even Chinese mobile they have Mirroring option. If Nokia return over Money then it will again out from Mobile industry.
So forget your loss and keep away from Nokia mobile...
Hello in devices with Stock Android like Nokia 3 you can Cast if you have a Chromecast, Nexus Player, or other device that can cast. With this, you can show your phone screen and audio on a TV.
To cast your phone, go to settings and tap on the search icon at the top of the settings and type 'Cast' then you can get the option to Cast your phone if you have a compatible device as I mentioned above. But you won't get the option like on other devices like chinese mobile to cast your screen to PC and other incompatible devices. However you can use third party apps on play store to do that. Thank you.
You can also use the Wifi Direct option if your TV or any other device support that technology. Go to settings. In Wifi Preferences and in advanced option you can find the Wifi Direct option. Thank you.