accounts-frontend/packages/app/components/profile/changeUsername/ChangeUsername.intl.json

{
  "changeUsernameTitle": "Change nickname",
  "changeUsernameDescription": "You can change your nickname to any arbitrary value. Remember that it is not recommended to take a nickname of already existing Mojang account.",
  "changeUsernameWarning": "Be careful: if you playing on the server with nickname binding, then after changing nickname you may lose all your progress.",
  "changeUsernameButton": "Change nickname"
}