Bullying happens in all aspects of life from school, to your workplace or closer to home. It has also now appeared online, when we use the Internet and social networks. It is important that young people feel able to report any problems to parents or adults.
If someone threatens or harasses you online you should take a screen grab or copy of what has been said
https://www.childline.org.uk/info-advice/bullying-abuse-safety/online-mobile-safety/
https://www.getsafeonline.org/safeguarding-children/cyberbullying/