WhatsApp can be freely used by anyone with a valid phone number but under certain conditions. One of them is to configure a username for the account, regardless of the number or type of characters it contains, as long as they do not exceed 25.
Given these conditions, many people choose to enter their real name, others use pseudonyms or initials. And this is the way in which they can be identified by other people with whom contact has been made through WhatsApp.
But if despite all these advantages, you still want to appear anonymous to another user, you just have to put into practice the following trick referring to the invisible characters of the Unicode system.
How to use WhatsApp without name?
Make sure you have WhatsApp updated to its latest version.
Enter from your browser at the following address: https://unicode-explorer.com/c/2800.
Once you are in the interface of this page, click on the Copy button.
Now, open WhatsApp, enter its configuration section and access the section to edit the user profile.
In the field to enter the name, delete the current name and make use of the Paste option.
To finish, confirm the action by clicking on OK. From now on, your WhatsApp name will be blank.