UPDATE: miHoYo has removed the ability for players to change their name as June 4th, the anniversary of the Tianmen Square massacre comes closer. There is no word on whether the feature will be readded or not afterwards.
When players pick one of Genshin Impact's twins, Aether or Lumine, they are called by their canonical name only once in the storyline.
Every other mention of the chosen character is by a player's username.
There is a way to change this, however, for players who are unhappy with the initial name they gave their Traveler.
How to Change The Traveler's Name in Genshin Impact
Though it seems the option has been removed for some Genshin Impact players, others can change their Nickname by opening the Paimon Menu and either selecting the icon next to their username or hitting the left d-pad button on their controller.
From there all that is required to change the Traveler's name is to hit the "Edit Nickname" button.
Keep in mind that this will not change the username players use to log into the game, just the name the Traveler is referred by in-game.
As mentioned above, the ability to change the Traveler's Nickname has been removed for some players, so the button may not appear in their Paimon Menu.
Changing the Player Avatar and Namecard
Players can also change their profile Avatar and Namecard from the Paimon Menu in a similar way to changing their Nickname.
Players have the choice of any character they have obtained to use as an Avatar, while Namecards can be earned through various Events, by raising a character's Friendship Level to 10, or by completing Reputation Quests in Mondstadt or Liyue.
Players can also showcase characters and Namecards they have obtained on their public profile through the options as well.