is there a link where i can change my username

https://support-leagueoflegends.riotgames.com/hc/en-us/articles/360037264394 here is the information about the username change.

i need help, please i have been waitinf for 3-4 hours can you send somoene to help me out??

i have a ticket open but its a computer i just want to change my username completely